At the age of 58, stuck in her house through the long nights of the coronavirus pandemic, Michelle Brennen started to spend more and more of her time thinking about the worst thing that had ever happened to her.She was 10, on summer vacation. She had been playing in the yard in Essex Junction, Vt., and when she came inside, she found her mother standing in the archway between the kitchen and the living room, crying.“Daddy’s plane crashed,” said one of her five siblings — she has never known which one. The information did not register; she thought they meant one of her father’s model airplanes. No big deal, she thought. Just glue it back together.It was 1973, a time when adults didn’t talk to children about death. That afternoon, a neighbor took the children to the beach so they wouldn’t see news coverage of the crash, among the deadliest in New England’s history.The following week, when their father was buried, they weren’t allowed to attend the funeral. When school started, a guidance counselor called her in and asked her how she was doing. Michelle said, “Fine,” and that was that.Maybe that’s why, all these years later, something kept steering Michelle’s mind back to the plane crash.Clearing out her mother’s basement after she died in 2021, Michelle found a cardboard box where her mother had stored everything related to the flight, Delta 723 — newspaper clippings, correspondence with lawyers, journal entries.Once she began reading, Michelle found that she could not stop. She was especially drawn by the dog-eared passenger manifest, 89 names on a battered sheet of paper. How many of them had left children like her behind? Where were those children now? How had their lives turned out?And so, planting herself in front of an iPad at the dining room table, she tracked them down one by one. She popped up in their DMs. She called their landlines. She invited them to exchange stories on a Facebook page. She hoped she didn’t sound like a kook.In her own way, she was exploring questions that have preoccupied the field of mental health. How does traumatic loss alter the course of a person’s life? Does grief subside more fully when left in a box, or when it is shared? Does it subside at all?These questions hung in the air on a Sunday morning in July, when Michelle, now 60, awaited the arrival of around 200 people, nearly all of them strangers. Over two years, she had managed to track down survivors for all but four of the 89 people who had been aboard the plane, and persuade them to gather in person on the 50th anniversary of the crash.She had chosen for the location of their one and only meeting an obvious and terrible place — Logan Airport, not far from the runway where Flight 723 had burst into flames.A ‘large, long flame’A rescue worker examines the charred fuselage of the Flight 723 jet on July 31, 1973.Charles Dixon/The Boston Globe, via Getty ImagesThe plane was descending through dense clouds surrounding Boston when something seemed to go wrong in the cockpit. “Going like a son of a bitch,” said the pilot, John Streil, to his co-pilot, Sidney Burrill, who was trying to line up the jet to approach the runway properly.Thick fog in Boston had caused many flights to be diverted, so Flight 723, from Burlington, Vt., had made an unscheduled stop in Manchester, N.H., to pick up stranded passengers. Most of them were probably looking at their watches, worried about making connecting flights.On the instructions of air traffic control, the crew had made a series of turns intended to align the aircraft with a localizer beam, which demarcates the centerline of the runway and acts as a guide for pilots in low visibility.But they were moving too fast — 237 miles per hour — and they were too high. They overshot the localizer, and then scrambled to correct course, descending too quickly.The crew had been told that the cloud cover was at 400 feet, and peered into the whiteness, expecting to break through at any moment. But a thick bank of sea fog was moving across the airport. They saw nothing.“OK, just fly the airplane,” the pilot said, according to cockpit voice recordings. Two seconds later, Mr. Streil understood that the plane’s flight director was malfunctioning, and he said: “You better go to raw data. I don’t trust that thing.”For the first time, his voice betrayed strain. “Let’s get back on course if you can,” he barked at his co-pilot. The plane was traveling at around 150 m.p.h. when it hit the concrete sea wall that separates the airport from Boston Harbor.Relief workers sift through the wreckage at Logan Airport in Boston. The crash of flight 723 was one of the deadliest in New England history.Joe Runci/The Boston Globe, via Getty ImagesThe impact shattered the plane, and pieces of the cabin rocketed forward onto the runway. A construction worker nearby described a “large, long flame” appearing on the runway, rising “as if it were a curtain.”When rescue workers arrived, they found fragments of the plane and its passengers scattered down the runway, covering an area the size of three football fields. There were blue and red seats, some with passengers still strapped in.The remainder of the aircraft had broken with such force that, a spokesman with the National Transportation Safety Board later said, “you could pick up almost any of the pieces in your hands.”Many things went wrong simultaneously during the landing, Paul Houle, a former U.S. Army accident investigator, concluded in his 2021 book on the disaster. The plane’s flight director was faulty; the air traffic controller was distracted; the crew had been misinformed about the weather. Each of these factors, he said, carried equal weight.But at the time, the public was offered only one explanation: pilot error. Aviation officials “would only say that the pilot, Captain John N. Streil Jr., was flying the jetliner 230 feet too low and 3,500 feet short of the usual touchdown point,” The Associated Press reported.Fishermen told The Boston Globe that the fog had been so thick that they hadn’t been able to see their hooks hit the water. “The goddamn fools, flying in this weather,” one of them said.The boxClearing out her mother’s basement after she died, Michelle found a box where her mother had stored every document related to the flight.On the day of her father’s funeral, Michelle watched the adults leave in their church clothes.She had shouted at her mother — she thought she was old enough to go — but now the fight had drained out of her, and she sat on a cement floor in an unfinished part of the house, behind a piece of lumber, where they couldn’t see her cry.To comfort her, an aunt promised to bring her a gift: a bottle of Shower to Shower baby powder. But nothing could comfort her.She came to understand her role in the family tragedy. “You knew something big was going down, and you didn’t make any waves,” she said. Her mother was “constantly trying to get us to go outside and play — go outside and play.”In all that silence, terrible thoughts snagged in her mind. The night before the crash, she had gotten into an argument with her father, and, “in my 10-year-old, very stubborn and bossy way,” muttered to herself: “I wish you would die.” This ate at her, this unforgivable thing, but she never told. Whom would she tell?And somehow it transpired that she did not quite take in her father’s death. Years later, she still sometimes thought she spotted him in crowds. She would look for him in Barre, Vt., where he had grown up. Her sister Denise, who was 8 when their father died, felt the same way. “I kept thinking for years that he was coming back,” she said.Her father, Michael Longchamp, was 39 that summer, working as a draftsman at an architectural firm. He was an outdoorsman and a former Air Force tail gunner. By temperament, he was preternaturally even-keeled. At home, he would lie back in an armchair and let his six children crawl over him like puppies.That summer was a perforated line, separating life with their father from life without him: Tear here.Michael Longchamp with his family.via Michelle BrennenPatricia Longchamp with her children one month after the crash. Michelle is third from left.via Michelle BrennenThe extended family closed ranks; their aunt moved her family back to Vermont so she could be near. Michelle remembers her mother, Patricia, as always busy in the years that followed. Chris was 9; Denise was 8; Anthony was 6; Renee was 5; and Joseph was 2. “It wasn’t like she could sit and cry over it with nobody around,” she said. “She had stuff to do.”In that sense, they coped well. They moved on. “My family did a fabulous job of making sure that we didn’t feel any repercussions over it,” she said. “You know, we didn’t dwell on it.” But something was off-kilter, like a bone that had not been set properly. Even today, she wonders: Who would they have been if their father had not died?After graduating from high school, she got a job at a flower shop and married her high school boyfriend, more or less to get out of the house.She is sure that would not have happened if her father had been alive. He would have insisted that she go to college. Maybe she would have followed her father into the military. At the least, she would have left Vermont. “I think about that every day,” she said.It was worse for her brothers, though. “You’re the man of the house now,” one of the grown-ups told Chris.“I think my mother, to her deathbed, would say that just crushed him,” Michelle said.When Michelle found the box in her mother’s basement, she realized how much her mother had carried alone. There were her father’s death certificate — “two broken legs and generalized thermal burns” — and her mother’s handwritten journals.“Anthony asked tonight to see a picture of his daddy, because he had forgotten what he looked like,” read one of the entries. “I showed everyone a picture and Joseph laughed right out loud and said, ‘That my daddy.’ It hurts so much sometimes I don’t think I can make it.”“In 48 years, we never knew that side of her, the pain she was going through,” Michelle said. She wondered if the box was a form of communication, whether she was meant to look inside.“My mother had saved that whole box of stuff,” she said. “And I’m thinking that maybe, I did it for her, too. Like, maybe in the back of her mind, she thought this was important.”On the phoneAl Holzscheiter, a building contractor from Texas, said the crash had “totally changed and rewired who I probably would be.”Tracking down the other families felt satisfying. When she finally did get her bachelor’s degree, racking up one or two credits each semester while working two jobs, she had majored in psychology. Now she rolled up her sleeves and began collecting data.There were, as a social scientist might put it, correlations. Many of the passengers’ children recalled feeling completely alone in their grief, excluded from the rituals of mourning. Douglas Watts, an IT manager in Portland, Maine, was 8 when his mother, Sandy, died in the crash. “It was basically: She died, we had a service, it was done,” he said. His job, he understood, was “to never do anything that brought pain or emotion to anybody.” So he did not cry, not once.Many shared the feeling that the crash had radically changed the circumstances of their lives, setting them on a new path. Albert Holzscheiter, a building contractor in Fredericksburg, Texas, was 3 when his father died in the crash. His mother moved the family to Key West, Fla., as far as she could get from the extended family in Vermont.“It has totally changed and rewired who I probably would be,” he said. “I do not know if I would recognize the person that I would have been.”Even their memories of the day itself lined up with hers. Cornelia Prevost, who was 12 when her father, Count Laszlo Hadik, died in the crash, had written a poem that made Michelle cry when she read it, it was so close to her own recollection.“A glorious, simple / summer day tripped / into slow motion,” it read in part. “Expectant, heavy calm / an approaching thunderhead / and sibilant grownups roboted. / We knew not to be boisterous.”But not everyone understood what she was trying to do. “I’m barely getting people to tell me who they are,” she complained a year into the effort. It was too painful, some of them told her. “You know, my family was ripped apart, and I can’t even talk about it,” she recalled some saying.Cindy Provost Long, 66, a nurse in Bennington, Vt., felt that way. She was 16 when the plane crashed; her grandmother, two cousins and her 14-year-old brother, Michael, were on board. She remembers a doctor coming “and giving my mother some kind of injection to calm her down.” After that, her mother “had, essentially, a nervous breakdown.”She never really got better. Ms. Long used to wait for the mail so she could throw out her brother’s Mad magazine, to spare her mother the pang of seeing it. When dementia clouded her mother’s memories, she said, it was a blessing.John N. Streil, the pilot of Delta Flight 723, shown in a family photograph.Jillian StreilFor Ms. Long, discussing the loss on Facebook was not therapeutic. The scab that had formed in her mind, slowly, over decades, was prized off, and she started having bad dreams again, lying awake at night, “asking what-ifs.” Michelle’s whole outreach project, she said, was “an intrusive act.”“It’s too late, and it’s still too personal,” she said. And as for getting together at Logan Airport? No, thank you. “I don’t understand how this could be, like, a celebration,” she said. “Is it the airport asking forgiveness? Is it Delta that is doing this? I don’t even know what it is.”Michelle didn’t argue when she got that kind of response. But there were a few families she kept going back to, because their story troubled her so deeply: the families of the men in the cockpit. Early in her research, she learned something she found wrenching. As New Englanders mourned the dead of Flight 723, some had turned their anger on the pilots’ families.“They got death threats over the phone. They got death threats in the mail,” said Hollie Streil, who married the pilot’s son, John Randolph Streil. The experience, she said, “turned his mother into an alcoholic.”Mr. Streil, who was 12 at the time of the crash, began drinking heavily in his teens, and struggled with addiction throughout his life. “He, his family, bore the brunt of everyone’s anger,” Ms. Streil said. “I just remember my husband just sitting and crying and saying they blamed him.”She and Mr. Streil divorced in 2013 but lived together until he died of a heart attack in 2015. Her feelings about the crash and its aftermath were complicated and dark. But Michelle kept reaching out to her, and Ms. Streil became convinced that her intentions were good.So she arranged to attend, with three children and two grandchildren.She was dreading it, she confessed. “This has been buried under the rug for so long. All of a sudden people are going to rip up the pieces,” she said.“I will be glad when it is over,” she said. “I don’t think I will ever go back into Boston.”In the ballroomThe night before the memorial, Michelle decorated the ballroom where the families would gather.On the night before the big gathering, Michelle was frazzled and anxious. She had developed a sinus infection, and was so hoarse she could barely speak. Also, she was acutely aware of the things that might go wrong.Culpability was litigated, slowly and painfully, for nine years after the crash. Passengers’ families sued Delta; Delta argued that the air traffic controllers were responsible; the pilots’ families sued the manufacturer of the faulty flight director.But none of it, not the settlements or the court decisions, fully put to rest the question of blame. Two years of research had given Michelle a sense of the anger that some families still harbored, burning as steadily as a pilot light.Now, at her request, they would all be in the same room, with an open microphone. This was a minefield. Delta had donated money for the buffet lunch. Then there were the Streils, whom she had coaxed into attending. What was she thinking?It was true, she had shaken things loose. Mr. Holzscheiter, who had driven 30 hours from Texas, felt a wave of sickening panic after he checked into his hotel; he wasn’t sure he could go through with it. His wife, Ginger, compared the gathering to the story of Pandora’s box from Greek mythology, releasing all manner of phantoms.On her way to the ballroom, Liz Axness, who lost her mother in the crash, found herself in an elevator with a group that appeared to be headed to the event. When she asked, “Who was your loved one?” one of them replied — meekly, she thought — that they were from Delta.“I’m like, What do you think I’m going to do, kick you in the tummy or something?” she said. “You weren’t even born.”The night before, Jim Fuller, a sportswriter who lost his mother and father in the crash, had met the Streils. It had been a pleasant interaction; they had participated in a memorial blood drive he had set up.He had nothing but compassion for the Streils; their family, he said, “had been through more than any of us.” He would never assign blame. But a question had gnawed at him since he was 8, and he could not help asking it aloud now.“Why,” he said, “would you try to land a plane if you can’t see the runway?”Dozens of family members attended in memory of Jim and Peg Fuller, who died in the 1973 plane crash.Coming to termsOne thing that has changed in this country since 1973 is the way we respond to traumatic losses.When a child dies in a car accident, grief counselors are on hand at schools, to help students process their feelings. Police officers attend debriefings. Bereaved people send out flares of raw grief on social media. This is viewed as healthy. With luck, it gives us closure.But researchers trying to pin down this phenomenon have been left with doubts. Two years after the terrorist attacks of Sept. 11, Roxane Cohen Silver, a social psychologist at the University of California, Irvine, and a team of researchers looked at a group of people who had been asked to describe their emotions on the day of the attacks.What they discovered, she said, was that “those who emoted most, wrote the most words, actually did the worst over time.” It wasn’t that emoting was bad, Dr. Silver said. More likely, those who emoted more were simply in more distress.Her research has also called into question a much larger assumption: that people who suffer terrible losses eventually come to peace with them. In a 1989 study, she and Rosemary Tait interviewed 45 older men and women — the mean age was 76 — about the worst thing that had ever happened to them. For most, it was the death of a spouse or a close family member.These were old losses; the average elapsed time was almost 23 years. What the researchers found was that the pain had not gone away. Seventy-one percent said they still experienced mental images or memories of the loss, and 96 percent said they sometimes ruminated about it. Thirty-seven percent said they were still searching for meaning in it.“There are some for whom resolution never happens,” Dr. Silver said. “And there is some acknowledgment that, for some people, they will never resolve their sudden tragic loss, and they will probably function well. It’s not that they will not be able to get out of bed. But they will not, quote, get over it.”Still, something seemed to be happening that morning in the lobby of the airport Hilton, as those who had come recognized one another. They embraced each other, squeezed each other’s hands. They ran their fingers over a memorial plaque of Vermont granite that had been mounted in the airport’s chapel.Michelle was anxious before the gathering, in a hotel ballroom at Logan Airport, not far from the runway where the plane crashed.It was a comfort. There were so many of them. “My mother was on the plane,” a woman in dreadlocks told a man in Bermuda shorts. “My father was on the plane,” he responded.Finally, they took their seats in a ballroom, where photographs of the dead were projected onto a screen. Michelle’s sister sang with her barbershop quartet. Someone read a poem by Robert Frost. Michelle said she hoped they could set aside whatever anger and bitterness remained, to honor the dead.Then Jillian Streil, the pilot’s granddaughter, made her way to the microphone. She was 37, a waitress in Manchester, N.H., with blond bangs and cat’s-eye glasses.She never met her grandfather, but when she searched online for information about the crash, the phrase that came up was “pilot error.” She had read through the passenger manifest many, many times. “I almost feel like it’s my responsibility,” she said.Standing before the passengers’ siblings and spouses, their children and grandchildren, she held up a piece of paper on which she had written down what she wanted to say.“He deserved to be remembered for more than this awful tragedy,” she said. So she said a few words about him. That he had been a devoted son. That he had loved to fly. That when he died, he had a son who was about to turn 13. That as his wife and son mourned, they absorbed the hatred of those who blamed him.“They are no longer with us, and that’s why I am here today, to speak for them,” she said.Standing up there, she set aside passages of the speech — things she had been thinking about for 20 years — because she couldn’t get through them.“From the Streil family, thank you all,” she said.She returned to her seat, looking pale.And then a row of people were lined up to put their arms around the young woman.The son of Bette Vincent, who died in the crash, hugged her.The son of Sandy Watts, who died in the crash, hugged her.The son of Al Holzscheiter, who died in the crash, hugged her.The sister-in-law of Michael Longchamp, who died in the crash, hugged her.The sister-in-law of Maria Abrams, who died in the crash, hugged her.Michelle hugged her. And, for the first time that day, she wept.A long line of people waited to embrace Jillian Streil, the pilot’s granddaughter.Closing the boxThen it was done. The families dispersed quickly, stopping by a desk outside to validate their parking tickets, vanishing into the hubbub of the airport.On the long drive back to Texas, Mr. Holzscheiter had time to consider something that had been proposed at the gathering: that this group reconvene every ten years. “I think the word ‘generations’ was used,” he said.He disagreed; his children didn’t have strong feelings about the crash, and he thought that was as it should be. “Daddy’s memory will die when I die,” he said. “My generation, and my mother’s generation, remembers them, and I think it should probably pass on.”Michelle returned to Vermont the same day, loading up her S.U.V. with tote bags and centerpieces. All morning, people had been praising her, thanking her for bringing them together, and this made her uncomfortable; she shook it off reflexively, the way a dog shakes off water.She was now finished with the memorial, a moment her friends and family had long pondered. What would she do without her project? The next day, she spent some time with her chickens. She went to see “Barbie” with her girlfriends.But it didn’t take long before she started thinking about the crash again. Strangers were reaching out through the Facebook page. She still had questions; she had never known what meetings her father had been headed to in Boston that day, and it bothered her.So her mother’s box of documents stayed in its spot at the dinner table, and before long, she was back at her iPad, looking for those four families she had never been able to reach.“I truly believe there is thin veil between heaven and earth,” said the priest at a memorial mass that morning.