Although police have not released the victim's name, the man who died is believed to be a 25-year-old Fremont resident.

Fremont police dispatchers received a 911 call at 11:30 a.m. of a man who drowned in Alameda Creek near Niles Canyon Road and Mission Boulevard, said Sgt. Paul McCormick.

A preliminary investigation revealed that the man jumped off the trestle and that he likely drowned, McCormick said.

The Alameda County Sheriff's Office responded to the scene and took over the investigation because Alameda Creek is in its jurisdiction. Divers discovered the man's body about 2:30 p.m., said Fremont police spokeswoman Geneva Bosques.

"He was with friends and they were all jumping for recreational purposes," Bosques said. "He jumped and did not resurface."

A cause of death had not been determined on Saturday afternoon, but no foul play was suspected and suicide was not a factor in the man's death.

Contact Natalie Neysa Alund at 510-293-2469. Follow her at Twitter.com/nataliealund.