A knock came on the cabin door, and someone — a steward or the father and son from the next room — had a warning for Elizabeth Lines and her 16-year-old daughter, Mary.

Wake up. Get moving.

"They were told, 'This is serious,'" says Bradford Wellman, 80. "'Get your life jackets on. And get up on deck.'"

On its 100th anniversary, the sinking of the Titanic remains for many an obsession. But few have as much reason as Wellman to be fascinated by the story.

His mother and grandmother made it to a lifeboat that night, Mary Lines clutching a flashlight from the cabin.

Absent that escape, Wellman said with a grin, "I wouldn't be here."

Wellman lives with his wife in a retirement community in Scarborough, Maine. His mother lived most of her life in Topsfield, Mass., a Boston suburb.

Mary Wellman seldom spoke of that dreadful April night in 1912, he recalls. Mother and daughter were on their way from Southampton, England, to New York to attend brother Howard's graduation from Dartmouth. By some accounts, they were traveling first class; Wellman thinks second class is more likely.

In any case, he said, the voyage began an interval of sorrow and horror that drove Wellman's mother to a mental breakdown.

She only began to speak of her experiences aboard Titanic with the publication in 1955 of the book "A Night to Remember" by Walter Lord, said Wellman. The author neglected to include her name among the survivors, and she contacted him about the error.

Perhaps the title had an impact, too, because Mary Wellman, who died in 1975, began to feel it was indeed a night to remember. "She started to talk about it," her son said. "But not a great deal."

It was a freezing, black night but a calm sea. Passengers faced the choice of being set adrift in lifeboats in the frigid Atlantic or staying aboard the unsinkable Titanic. At first, they mostly chose the latter. (The Titanic had only enough lifeboats for one-third of the more than 2,000 passengers.)

"Hers was one of the lifeboats they let go unfilled," said Wellman. "It pulled away." And there must have been misgivings on board because there was virtually nothing in the way of survival gear.

"Just the oars," he said.

In their lifeboat on a dark night, Mary and her mother were at least grateful to have the flashlight, hoping if worse came to worst they could use it to alert a passing vessel, said Wellman. "It was the only light they had."

Before their eyes, slowly but inexorably, the mighty Titanic disappeared into a black ocean. All lifeboats gone, desperate people began to leap into the icy water.

Heart-rending pleas for help reached the Lineses and others who "wanted to go back and pick people up. The crew would not do it. They were afraid the boat would be swamped." Wellman shrugged grimly. "Understandably."

He added, "Mother remembered all her life the cries of the people in the water, dying."

As those desperate voices weakened and died out, a freezing night followed, the huddled survivors not knowing what would become of them. Mary would later speak of the kindness of passengers and crew aboard Carpathia, the British steamship that picked them up in the morning.

Meanwhile, her father, a doctor working in France for an American insurance company, was frantic for days until he learned his wife and daughter had survived.

In the aftermath of the disaster, the family retreated to Paris. But before too many months, in 1914, World War I broke out. Dr. Ernest Lines devoted himself to treating French soldiers horribly mutilated in the fighting, paraplegics and quadriplegics.

Mary worked as a nurse's aide caring for casualties streaming in from a front a mere 20 miles off. Again, she endured the cries of the dying.

Mary Lines had recovered from what her son describes as a nervous breakdown in 1920 when she married Sargent Holbrook Wellman, an American soldier she'd met in France. They settled in Massachusetts in 1923.

The Wellmans had three children, then grandchildren. The family retained Mary's flashlight along with a reservation ticket for a Titanic deck chair, keepsakes of a calamity.

Looking back on his mother's brush with history, Bradford Wellman said, "I don't think it's changed my life." His mother was a cheerful person. And knowing what she survived made him "more respectful" of both her and his grandmother.

Unafraid of the sea, Wellman said he's made several trips to Antarctica aboard cruise ships, adding: "I've seen a lot of icebergs."

Yet, he's never seen the Titanic movies. Nor would he join a sea excursion to the site of the wreck off the coast of Newfoundland.

Museums and articles about the Titanic do draw his attention. Asked why the story endures, he citeed some of his reading.

"The sinking was a disillusionment, a tragedy of the newly engineered mechanical world," he says. People had marveled as one incredible invention followed another, electric engines and lights, automobiles, moving pictures, telephones, ships with massive propellers shrinking the seas.

"Suddenly, one of these great wonders engineered by mankind was flawed," he says.

Less flawed were the men who stood to one side and allowed mostly women and children to access the lifeboats — "and the wives who decided to stay with their husbands."

He tells his mother's story with the ease of someone who has shared the same tale many times before. But there is a reason he hasn't seen the movies.

Wellman recalls visiting a Titanic museum in London and pausing over an engagement ring recovered from the wreck. Passing the various exhibits he'd been fine, but now at the end he stared at that ring, a symbol of loss, of interrupted dreams, of all the cruel memories his mother had carried in her heart.

And he began to weep.