Roger Parrish was a teen-ager with a golden touch, a star athlete and straight-A student at Columbia's Wilde Lake High School who entered Brown University last fall--and quickly won a spot on the fastest freshman crew team in the prestigious school's history.

Parrish, his friends said, thrived on an exhausting cycle of science classes and afternoon practices as a member of the crew team's "boiler room," the rowing positions requiring immense stamina and strength. But Parrish also loved to relax, and was looking forward to spending his summer break with his mother in Columbia, classmates said.

Sunday, after competing in a three-day regatta in Syracuse, N.Y., Parrish stopped over at his grandparents' house in the New York City borough of Queens. He went to bed at 9 p.m., as was his habit, and died in his sleep less than eight hours later.

Word of his death, which New York City's medical examiner said was "apparently natural," but still unexplained, stunned his family and friends in Columbia and teammates at the Ivy League school.

"I just don't know what I'm going to do without him," Irene Parham, Parrish's mother, said from the family home in Columbia's Wilde Lake Village.

"In a way, not knowing the reason why he died makes it better," she said. "I'm taking it that it was an instantaneous thing."

Dr. Elliot M. Gross, New York City's chief medical examiner, said an autopsy showed no signs of a heart attack. "If it had been a question of an enlarged heart or a cerebral hemorrhage, then those signs would have been apparent," said Gross, who has ordered chemical and microscopic tests to determine the cause of Parrish's death.

Results from those tests, which will be conducted in New York, will be available within two months and will include an analysis for traces of drugs, he added.

Parrish's mother said her son never used drugs and never drank more than one or two beers--and then only at parties. "He didn't smoke at all," she said. "When he came down this spring for the senior prom, he turned down a glass of champagne."

"There was a great fire in Roger, an urge to be successful," said Will Scoggins, the coach of Brown's freshman crew team. "There were people who were bigger and stronger than him, but he kept on working himself up.

"Roger was not a wild and crazy guy," and adhered to a strict training program that barred alcohol, Scoggins said. "He was a perfect example of the crew member . . . who is self-reliant and a great team member as well."