That Valentine's Day at Idlewild Airport, sometime around 7:30 p.m., the 18 skaters and six coaches who made up the U.S. figure-skating team boarded a Boeing 707, Sabena Airlines Flight 548, bound for Brussels, Belgium. Their mood was so joyful that someone suggested they pose for a photo on the jet's portable staircase.

That black-and-white photograph would capture their smiles, their anticipation, their optimism. But by the time it was developed, they were all dead.

Fifty years ago this week, that plane plummeted into a Belgian cabbage field. All 72 people on board, plus a farmer on the ground, were killed.

And while it might seem counterintuitive, or even ghoulish, the tragedy helped produce-or at least sustain-a rich tradition of American figure skating.

Many of the superb U.S. skaters who have followed benefited from a memorial fund established that year to honor the victims. Many more learned from European coaches such as Italy's Carlo Fassi and Britain's John Nicks, who were brought to the United States to replace the dead.

"It's possible to look at the terrible tragedy and see it as the start of a legacy," said Nikki Nichols, a former skater who has written a new book on the crash called Frozen in Time.

Ron Ludington, the guru of the University of Delaware Figure Skating Club - where both Johnny Weir and Kimmie Meissner trained - has been to every World Championships since 1956.

Except one.

Ludington, who lived in Connecticut in 1961, had just gone through a divorce. Low on cash, he decided not to make the trip to Prague.

Conversely, Douglas Ramsay finished fourth at the national championships and wasn't supposed to go. But the third-place finisher, Tim Brown, became ill in Philadelphia, so Ramsay took his place.

By 1961, the older generation of U.S. skaters, such as Carol Heiss and David Jenkins, the 1960 Olympic gold medalists, had retired. A new crop, and the coaches who had nurtured it, boarded the plane that night.

Those that did so included three members of American skating's royal family: Laurence and Maribel Owen, and their mother, Maribel Vinson Owen, a nine-time national champion.

Maribel Vinson Owen coached her daughters. Her oldest, Maribel, had won the U.S. pairs title that year skating with Dudley Richards, who also traveled to Prague.

Laurence, meanwhile, at 16 the national women's champion, may have been the most promising skater of the bunch.

"She was just coming into her own," Nichols said. "That was an era when television was just starting to recognize skating. Laurence was a wonderful skater and a beautiful girl who would have been a breakout star. "

Bill Pipp made the trip, too. A champion skater in Allentown, he had become a successful coach in California. Back home, he had a promising 12-year-old pupil named Peggy Fleming.

Other passengers included Larry Pierce and Diane Sherbloom, the reigning ice-dancing champions; Robert and Patricia Dineen, ice dancers who decided not to bring along their 9-month-old son; and Stephanie Westerfield, the runner-up to Laurence Owen.

Their itinerary was simple. They would fly out of New York at 8 p.m. After arriving the next morning in Brussels, they were to make connections to a flight that would take them behind the Iron Curtain, to Prague.

By all accounts, Nichols said, the long, dark trip across the Atlantic was uneventful. As the jet neared the Belgian airport, perhaps just 25 miles away, ground control lost contact.

It was just before 9 a.m. in the village of Berg. Farmers were readying the fields for planting in the spring. A Catholic priest was walking outside his church when he heard the desperate drone of a plane's engine.

"I saw a flash," he later told investigators. "Then the plane started to lose height."

Everyone on board, all 61 passengers and 11 crew members, presumably died instantly when it exploded on impact. A farmer was killed when debris hit him like mortar shrapnel.

Kendrick Kelley, a U.S. skating judge who already was in Europe, hurried to the site when he heard the news. He later described it as a "shocking and fearful scene."