SAN DIEGO (CBS 8) - An 18-year-old man is fighting for his life after being shot at a house party Saturday night in Grant Hill. 

The shooting happened in the 2600 block of Island Avenue around 11:30 p.m. when the 18-year-old man got into a fight with a 21-year-old man at the party. The fight was broken up and the two were separated. However, a few minutes later, the 21-year-old man returned with a gun and shot the victim. 

The victim was transported to the hospital with life-threatening injuries.

San Diego Police gang detectives are investigating the shooting.