There is no gentle way to say that the poet Gregory Orr, at the age of 12, accidentally shot and killed his younger brother Peter. It happened one cold November day in the 1950s in a field on his family's property in upstate New York. As Orr tells it in The Blessing: A Memoir, just published by Council Oak, the plan had been for just Greg and his older brother, Bill, 14, to go out with their father; it would be the first deer-hunting season for both boys. But the younger Orr brothers, Jonathan, 10, and Peter, 8, begged to come, and their parents agreed. And so Peter was there, standing behind him when Greg, in his excitement over killing his first deer, pointed his rifle over his shoulder and pulled the trigger. The chamber was supposed to be empty; it was not. Peter lay dead on the ground.

Four decades later, PW sits with Greg Orr in a coffee shop bursting with life in Charlottesville, Va., where Orr has taught creative writing at the University of Virginia since 1975. Orr is a slim, shy but friendly man in sandals, jeans and a polo shirt. He has thick black hair, a graying moustache, and the haunted look of someone who has seen something terrible that you have not. Baroque music brightens the air; young people, mostly mothers with toddlers, enjoy late-morning conversations. Without doubt we are here, in the present, but PW and Orr are also back there, on that shattering fall day, when Orr cried "I didn't mean to do it!" and ran to the house, hiding in his room and watching from the window as an ambulance took his dead brother away.

How many times has Orr relived the day? How many poems has he written about it? Poems like "A Litany," in which he remembers Peter "falling beside me, the dark stains already seeping across his parka hood." Author of eight poetry collections, including The Caged Owl: New and Selected Poems (2002), from Copper Canyon, Orr has approached the horrific childhood event many times in his poetry. But he has now turned to memoir, he says, to "go beyond making the moment coherent, as I can in a poem, to making the entire life coherent." In the process he examines behaviors that will shock readers as much as the killing itself: the utter silence of Orr's mother, father and siblings about the death. "No one spoke to me about Peter's dying," he writes. Shortly after the accident, he learned that his father, a country doctor and womanizer with an amphetamine habit, had accidentally shot and killed his own best friend at the same age. There was to be no discussion about that either. "My father couldn't talk about either death," he says. "Nor could he talk about the earlier death of Christopher, a brother of mine who at age three climbed from his crib and swallowed a bunch of pills from my father's desk and died."

Orr spent years overwhelmed by grief and guilt, compounded by the early death of his mother, whose funeral Orr's father would not allow the children to attend. The author's search for meaning took him from seeing himself as Cain in the story of Cain and Abel, to joining the civil rights movement at age 18 to discovering the healing power of writing lyric poetry—the subject of his Poetry as Survival (University of Georgia Press), also just out.

"Six years ago, my father was beginning to die of prostate cancer, and I thought finally we might be able to talk," says Orr. "But he said, 'No, you don't talk about things like that.' That opened the wound up all over again. Here is this person, who is dying, the last person I can talk to about this, and he won't talk. I am just going to have to write my way out of this in a memoir."

As The Blessing covers only Orr's first 19 years, readers will not have the benefit of knowing that he went on to complete a B.A. at Antioch in 1969, took an M.F.A. at Columbia, and met his future wife, Trisha, a painter, at the old Papyrus bookstore on Manhattan's Upper West Side, where Orr worked as night assistant manager. Married in 1973, the couple has two daughters. Orr agrees that marriage and family have helped heal him. "I'm a happy person," he blurts out.

And yet: Trauma has a way of reasserting itself, says Orr. "Periodically, I would be overwhelmed by despair. It comes back like that." For Orr, writing the memoir was an effort to sort it out. If his father would not help him, he would do it on his own. "I showed the manuscript to my father before he died. He was very angry. Then I showed it to my siblings. My sister and my older brother called the book a betrayal of my family. They said they would never speak to me again. My younger brother read it, wept, and said: 'Every word is true. Thank you.' "

Orr wrote the memoir three times. An agent found interest at several trade houses, but "they wanted me to sensationalize the story of my family. Curse my soul, I listened and wrote that book. But I realized it wasn't the way I wanted to represent my life." Later, another agent, Andrew Blauner, placed the final version with Council Oak. "They let me write the book I wanted to write."

From early on, Orr knew the book would open and close in fields. In the first field, Peter dies. In the second, Orr walks with a high school teacher through fields in Bolton Landing, N.Y., near Lake George. They were filled with giant metal figures created by the great American sculptor David Smith, who had just recently perished in an auto accident. "It was a moment of redemption," he says, "seeing those figures coming up from the field. I could do this—it was possible not just to destroy, like I did with my brother, but also to create. I had found meaning in my life."