A woman was killed and three men were badly wounded in a shooting in South El Monte early Saturday morning, police said.
The shooting occurred shortly before 3 a.m. at a warehouse party in an industrial area around Chico Avenue and East Rush Street.
About 40 people, most of them in their early 20s, were in attendance when shots rang out. Homicide detectives have detained about 20 witnesses and were in the process of interviewing them Saturday, Sheriff's Lt. Patrick Nelson said.
The motivation for the shooting appears to be an altercation that broke out among some of the partygoers, Nelson said. It is unclear why they were fighting, he said.
A sketchy description emerged of the attackers: two men wearing hooded sweatshirts, possibly escaping the scene in a dark sedan after the shooting, Nelson said.
The party was possibly a rave-style affair with alcohol but no apparent drug use. "I doubt it was permitted, but I'm sure the investigators will look into it," Nelson said.
The Los Angeles County coroner's office identified the victim as Clara Myung Hee Chun, 26. The cause of death was a gunshot wound, coroner's investigator Jim Blacklock said.
The three injured men were transported to a local hospital, where one was listed in critical condition and the others stable, Nelson said.
Since January 2007, at least 20 homicides have taken place within two miles of the location of Saturday's fatal shooting, according to data collected for The Times' interactive Homicide Report.