There are no self-help books for those who have unintentionally killed someone. Illustration by Brian Stauffer

Until 3:35 P.M. on June 15, 1977, Maryann Gray was happy. She was twenty-two, and had just decided to take a leave of absence from Miami University, in Oxford, Ohio, where she was pursuing a master’s degree in clinical psychology. Graduate school had been her mother’s idea, and Gray was unpleasantly surprised by how scientific the program turned out to be. Inside the front cover of her statistics textbook was a squashed bug, which she had circled and labelled “Maryann at the end of Stat.”

That summer, Gray was preparing to move into a ramshackle Victorian mansion in a neglected area of Cincinnati, which its residents called an “urban commune.” There, she hoped, she would eat curry, burn incense, and talk politics late into the night with new friends. Her father, a businessman, and her mother, a homemaker, who lived on the Upper East Side of Manhattan, were not supportive of the plan. But Gray couldn’t wait to move in. She spent the day painting her new bedroom yellow.

By the afternoon, Gray was sweaty and paint-stained, and she decided to go back to her boxed-up apartment in Oxford to take a swim. The hot, hour-long drive crossed through suburban sprawl and then into emerald countryside. Gray had the windows of her father’s 1969 Mercury Cougar down, and the radio tuned to the news. She was only fifteen minutes from the apartment, driving at the posted forty-five miles per hour along a wooded, two-lane country road, when she saw a pale flash and felt a bump.

The statement Gray gave to the police later that afternoon is written in the neat script a young student might use on a final exam: “A child (blond male) ran into the street from my left, running in front of the car. I tried to go around him (left) but couldn’t get by. I hit my brakes instantly + skidded to the left.” The signature at the bottom of the page looks as though it had been written slowly and with care.

When Gray read the affidavit forty years later, she was surprised by the precision of her account. “There was no way I actually remembered that,” she told me. “Hitting him I remember, and I remember sort of pulling over on a side street, getting out of the car, and there I lose a few minutes.” Gray recalled crouching behind a bush, terrified and hiding. “I remember thinking, What’s that noise?, and then realizing it was me, screaming.” She was still concealed by the shrubbery when the boy’s mother ran out of her house and began to wail. “She was with two women, and her knees buckled. She began to fall, and they held her up,” Gray said. “She wanted to go to him, of course, but they held her back.”

The police arrived about twenty minutes later, and, rather than wait for an ambulance, they put the boy in the back seat of a squad car and drove him six miles to the hospital, where, Gray later learned, he was pronounced dead on arrival. Only after the boy had been taken away from the bloodied road did Gray emerge. A few policemen had stayed behind, and she approached them, with one hand raised. “Like a schoolgirl,” Gray recalled. “I was so young.” Her voice caught. “I said, ‘I did it. I did it.’ ”

She was ushered into the back of a police car, where she sat until a woman who lived nearby approached, offered her a cool towel, and asked an officer if Gray could wait at her house instead. The officer agreed, and Gray sat in the kind stranger’s kitchen, sipping water. It was early evening by the time the Butler County sheriff’s office finished its site evaluation and asked Gray if she would be O.K. driving home. She said no. A professor picked her up and persuaded her to call her parents, in New York. “I said, ‘Mommy, Mommy’—and I never called her that—‘it was an accident,’ ” Gray recalled. Her mother replied, “Of course it was.”

Gray’s father flew out and took care of logistics. He called the insurance company, got the car towed, hired a lawyer, and paid the condolence call. Gray spent the week refusing to leave her old bedroom. “I had what I now consider to be a hallucination,” she told me. “I heard this voice, so clearly, saying, ‘You took a son from his mother and your punishment is that you can never have your own child.’ ” She told her therapist, whom she had been seeing for two years, that she was afraid the accident would ruin her forever.

In the following months, Gray drove slowly and uncertainly. She would see vague figures in the road, slam on the brakes, and then realize that nobody was there. An insect hitting the windshield could send her into a panic. She didn’t know how to act around her new roommates, who treated her with a kind of hesitant benevolence. “Here I was in this house that was all about peace and love and community, and I had just killed a kid,” Gray said. “I really wanted these people to like me and to accept me, so I just tried to act sad but not crazy.”

By the first anniversary of the accident, Gray was packing up her yellow bedroom. She took on odd jobs—at an exercise studio and then at an accounting firm—and lived with a roommate whom she rarely saw. In 1979, she moved to Southern California and returned to graduate school, at U.C. Irvine. In Gray’s telling, her life improved with the elegance and the inevitability of a film dissolve. “It was a new start,” she said. “I felt like I was leaving the horribleness behind.” She loved her academic program, made friends, and went to the beach. But the accident remained with her. She said, “There was this voice: ‘You don’t deserve to feel happy. Look what happened last time you felt happy.’ I lived with a ghost, with this child inside me, speaking to me, not very kindly. But I never talked about it.”

There are self-help books written for seemingly every aberration of human experience: for alcoholics and opiate abusers; for widows, rape victims, gambling addicts, and anorexics; for the parents of children with disabilities; for sufferers of acne and shopping compulsions; for cancer survivors, asexuals, and people who just aren’t that happy and don’t know why. But there are no self-help books for anyone who has accidentally killed another person. An exhaustive search yielded no research on such people, and nothing in the way of therapeutic protocols, publicly listed support groups, or therapists who specialize in their treatment.

According to the Centers for Disease Control and Prevention, in 2015, the most recent year for which data are available, there were nearly a hundred and forty-seven thousand unintentional-injury deaths in the United States. About a quarter were caused by motor-vehicle accidents; the total also includes falls, firearm mishaps, accidental poisoning, and all the other inconceivably varied ways a healthy person’s life might end. The C.D.C.’s reports are broad and terse; they describe how we die, but not why. Of the more than thirty-six thousand fatal traffic accidents in 2015, for instance, we don’t know how many were the result of a single car hitting a tree, how many were head-on collisions in which both drivers perished, and how many were caused by a person who walked away physically intact but psychically wounded.