A former Duke University basketball team captain jumped to his death Tuesday from the roof of a private athletic club in Midtown, police sources said.

Tom Emma, 49, jumped from atop the New York Athletic Club at 180 Central Park South shortly before 11:30 a.m.

Police found his body on the second-story landing of the Jumeirah Essex House next door. He was dead, cops said.

Emma, who lived on the upper East Side, was a member of the club, which has a common area on the roof. He did not leave a suicide note, police sources said.

"I can't believe it," said Johnny Dawkins, head coach for Stanford University's basketball team and Emma's teammate at Duke.

"He was a great guy," Dawkins said. "I have nothing but respect for him as a competitor. My thoughts and prayers go out to his family."

Billy Bitter, 22, came to the NYAC after hearing of Emma's plunge.

"He was my trainer," Bitter said. "He was a great man. He was awesome."

Relatives told police that Emma had been depressed, sources said.

"Everyone is shocked," a relative said over the phone before declining further comment.

Emma was team captain for the Blue Devils in 1983, his fourth season with the school. He was drafted by the Bulls the same year, but never played for the team.

The hoops player - a high school star in his native Manhasset, L.I. - penned a book titled "Basketball Player's Comprehensive Guide to Strength Training."

He was president of Power Performance, Inc., a company devoted to training young athletes.