SAN DIEGO — Police on Thursday identified the man who was shot to death at a San Diego recreation center last week.

The shooting happened before 7 p.m. Friday at the Montgomery Waller Recreation Center in the Otay Mesa West neighborhood. There, officers found Robert Simmons, 20, suffering from gunshot wounds, San Diego police said in a news release. He was pronounced dead at the scene.

A second victim, a 19-year-old man, was taken to a hospital and was expected to survive. His identity has not been released by authorities.

Homicide detectives believe the victims were issued a “gang challenge” by a member of a group when they arrived at the recreation center, police said.

The group started throwing glass bottles at the victims before at least one of the group members started firing a gun at them, according to police. The group then left the area.

Detectives say a white sedan was seen leaving the recreation center after the shooting, speeding eastbound on Coronado Avenue, but they were still determining if or how it was involved in the shooting, police said.

Anyone with information about the shooting was asked to call the SDPD Homicide Unit at 619-531-2293 or Crime Stoppers at 888-580-8477.