FENNVILLE, Mich. - One moment: a perfect shot to end a perfect season. The star player, just 16, lifted off the floor in celebration. Teenagers triumphant, crowds cheering, the district playoffs ahead, the future open wide.

The next: Wes Leonard on the gym floor, his enlarged heart failing, his life fading just a few moments after his victory layup. Packed bleachers suddenly stunned by an event that made basketball seem a distant, unimportant memory.

A day after Leonard died from an enlarged heart, this small town near Lake Michigan remembered an "all-American kid" whose athletic heroics had been local legend since middle school, when opposing coaches sometimes asked to see his birth certificate, not believing someone so young could be so skilled.

"He was a good kid, a good friend to have and a good person to hang around with," DeMarcus McGee, who played football and basketball with Leonard, said between sobs. "You never thought it could be him. He was so healthy. It shouldn't happen."

On Thursday evening, Leonard sent the ball through the hoop from close range with less than 30 seconds left in overtime. The final shot gave Fennville High a 57-55 victory over Bridgman High and a 20-0 regular season.

After the teams exchanged handshakes, Fennville players celebrated. Some began scrambling to organize a team photo that would commemorate their undefeated record. That's when the 6-foot-2, 215-pound Leonard collapsed, with an estimated 1,400 fans watching.

Video   Player dies after making game-winning shot March 4, 2011: A Michigan high school basketball player makes a game-winning shot, protecting his team's undefeated season, then collapses and dies on the court. Msnbc's Richard Lui has the details.

"Thirty seconds earlier, he was laying in the winning bucket," said Ryan Klingler, basketball coach in Fennville, about 200 miles west of Detroit. "And then 10 seconds later ... everything's pulled out from under you, from out of nowhere."

Leonard was rushed to nearby Holland Hospital, where paramedics performed CPR before he was pronounced dead. An autopsy conducted Friday by the Ottawa County medical examiner showed Leonard died of cardiac arrest due to an enlarged heart.

"It shouldn't have been like this," teammate Adam Siegel said. "Too young."

Medical examiner David Start said the stress Leonard placed on his heart through athletics could have played a role, but his death could not be easily explained.

"Why at this event as opposed to another basketball or football game, I don't know," Start told the Grand Rapids Press. He did not immediately return a call from The Associated Press.

Grief counselors were available Friday for students at the school. Delivery trucks dropped off trays full of flowers. Students made signs in tribute to Leonard and planned to display them in the hallways.

Many who knew Leonard said he was destined for athletic greatness from a young age. He was a top performer in baseball and football, too.

Vicki Lepior, who owns a roofing company, used to coach baseball against Leonard when he was a fourth-grader.

"When I saw him pitch, I told my boys, 'You better move back in the box just a little bit,'" Lepior said of the boy she called "Big Man Wes."

"He was just the kid that everybody loved, and there isn't a mother on Earth who doesn't feel (what his mother) feels."

Chad VanHuis, who once umpired Leonard's middle-school baseball games, remembered opposing coaches asking to see his birth certificate.

"He was very courteous. He was the nicest kid. You'd think with his star potential, because he's so gifted, he'd be cocky, but he never really was that way," VanHuis said.

When he reached Fennville High, Leonard really took off, playing as a starter for three years on the football team, first as a receiver, then as a quarterback and defensive end.

Hannah Foslien / Getty Images The Week in Sports Pictures

"He had a personality that, when people were around him, they played better," said Tim Schipper, Leonard's football coach. "Everybody around him played better, because he was a leader and the best athlete."

Schipper had expected Leonard to take his talents into college athletics at some level, although his prospects were unclear.

Leonard, who played basketball as a freshman and then spent two seasons as a starter, led the Blackhawks throughout the 2010 season.

"He was just an amazing kid," Klingler said. "What made him special is he had a passion about everything he did. That's what separated him — his passion. He had a passion to compete. He had a passion to be his best."

A visitation for Leonard was set for Sunday, with a funeral Tuesday.

The Fennville team is scheduled to compete in the Class C district playoffs Monday, but officials at the high school with more than 400 students had not decided Friday whether to play the game.

"That's way, way down the road," Klingler said. "We're going to make sure we're all in a good, healthy place before we decide on anything."

Leonard's mother, Jocelyn, is a choir teacher at the middle and high schools and director of Fennville High's production of "How to Succeed in Business Without Really Trying." A performance of the musical scheduled for Friday was canceled, and it was uncertain whether the Saturday and Sunday shows would happen, either.

Fennville Superintendent Dirk Weeldreyer remembered Leonard as "the quintessential all-American kid."

"Beyond his outstanding athletic abilities, Wes was a better person," Weeldreyer said. "His fellow students liked and respected him. Their grief speaks volumes about the high regard in which Wes was held."