They carried fresh flowers and ancient prayers. One young man stood over the open grave and read the 23rd Psalm, the one about walking through the valley of the shadow of death without fearing evil.

And when it was over, seven solemn seniors from the Roxbury Latin School — crisply dressed and ramrod straight — delivered James McDermott to his eternal rest last week in an unmarked grave at Fairview Cemetery in Hyde Park.

They’d never met the man. In fact, they hadn’t learned his name until a few minutes before when the young pallbearers assembled inside the Robert J. Lawler Funeral Home in West Roxbury as a hearse idled outside in the cold.

“We do it because it’s the right thing to do,’’ 18-year-old Ben Rivitz said. “We’ve been really lucky in life. We all here have family and friends who would help honor our lives, but Mr. McDermott, sadly, does not.’’

No, at the end, Mr. McDermott was alone. The 54-year-old man, described as homeless, drowned in the Charles River in July. His body had been stored since then at the medical examiner’s office, one of hundreds over the years that Bob Lawler — often by himself — has buried.

“If I go by myself, I’ll bring a book with me and say a prayer,’’ Lawler told me at his funeral home office. Why? “Because they deserve to be buried. They shouldn’t have to lie there for months on end. This poor guy’s been there since July.’’

There are plenty of others lying in refrigerated compartments where Mr. McDermott’s body had been stored for too long. Here’s the problem: Only a handful of funeral directors in the state volunteer to bury them. Graves are expensive and hard to find. And it’s been decades since the state increased the $1,100 stipend it provides to defray costs of burying the poor.

“I have to go out and try to find a grave,’’ said Lawler, 60, whose father was also a funeral director and often buried those without means or family. “He always told me to keep doing it, and I’ve been doing it since I was 18. I don’t mind doing it every once in a while because I always tell Mike: I’ve got to buy my way into heaven.’’

Mike is Mike Pojman, the assistant headmaster at Roxbury Latin, who inaugurated the high school’s participation four years ago. Mr. McDermott’s funeral was the 58th at which Pojman’s students have served as pallbearers for the homeless or indigent.

“I don’t think you can confront what your life is supposed to be until you confront what’s on the other end of it,’’ Pojman told me as we stood over the grave in what is known as the City Poor Lot, a sloping expanse of unmarked graves that is rapidly filling up.

These 17- and 18-year-old young men sat in quiet dignity, awaiting instructions from Lawler. There was no jocularity. No smiles. No chatter.

Pojman recalled the recent reaction from an especially gifted but stoic student: “He said, ‘I see this as a caution, because what’s the difference between his life and mine? If he knew thousands of people through his life and ends up alone, I wonder what went wrong. I want to make sure that doesn’t happen to me.’?’’

Last week, the students carefully carried Mr. McDermott’s remains from the hearse and inched their way to a stark and muddy grave.

Lawler, standing to one side, began with a prayer, and the boys, in turn, recited their own.

Then it was time for a final offering: “Help us to be mindful of the thin line between the comfort and abundance of our own lives and the hardship and solitude of his,’’ the boys recited in unison. “He died alone with no family to comfort him. But today, we are his family. We are here as his sons.’’

Ben Rivitz and his classmates placed their brightly colored flowers on Mr. McDermott’s simple pressed-wood casket. Then the somber-faced seniors climbed aboard a white school van, each carrying a life lesson that no one can learn in a book.

Thomas Farragher is a Globe columnist. He can reached at thomas.farragher@globe.com.