Wes Leonard of Fennville High died Thursday night, Holland Hospital spokeswoman Deb Patterson said. A cause of death has not yet been determined.
Paramedics performed CPR on the 16-year-old before he was pronounced dead at the hospital, Patterson said.
Leonard, a junior who also excelled as the quarterback of the Blackhawks football team, was "by far the best player on that basketball team - outstanding athlete," said coach Mike Miller, whose Bridgman team lost 57-55 to Fennville Thursday night.
Chad VanHuis, a 21-year-old Fennville High graduate who once umpired Leonard's middle school baseball games and was his camp counselor, heard that Leonard had collapsed before heading into work.
During his break around 1:30 a.m., VanHuis, an assembly line worker at an auto glass factory in nearby Holland, logged on to Facebook and learned of his friend's passing.
"I couldn't believe it," said VanHuis, who remembered opposing baseball coaches asking to see his birth certificate, not believing a 12-year-old could be so big and skilled.
"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."
On Thursday, Leonard, who earlier this season eclipsed the 1,000-point mark for his high school career, laid the ball in with less than 30 seconds remaining. Bridgman wasn't able to score during the ensuing trip down the court, giving Fennville a 20-0 season. Leonard fell to the ground after teammates and fans rushed the court.
"Obviously, in the midst of celebration, I think 'shocking' is exactly the word," Fennville Superintendent Dirk Weeldreyer told the paper before an ambulance carried Leonard away from the high school.
Leonard is the second Fennville athlete to die in 14 months. Wrestler Nathaniel Hernandez, 14, died in January of last year after suffering a seizure at home following his participation in a high school wrestling match.
In an interview with the Sentinel at Tuesday's practice, Fennville coach Ryan Klingler talked about how Leonard had a great drive to succeed and that he saw the "bigger picture."
"That's what makes him a little different. He takes care of his body better than probably anybody I've ever coached," Klingler said. "Spends a lot of time on his own in the weight room. He's a special kid."
Fennville is about 200 miles west of Detroit.