LOS ANGELES, Calif.–A 16-year-old boy accused of fatally shooting another 16-year-old boy inside downtown Los Angeles’ Third Street Tunnel was a member of a rival gang, and the teens had been attending a continuation high school class designed for “at-risk youths,” police said today.

The shooting occurred about 3 p.m. Tuesday just west of Hill Street, according to the Los Angeles Police Department.

Authorities withheld the name of the fatally wounded boy, who died at a hospital, pending notification of relatives, coroner’s Assistant Chief Ed Winter said.

Two LAPD detectives who were driving in the area heard several gunshots and arrested the suspect, who allegedly had a revolver in his waistband, said LAPD Lt. Paul Vernon of the Central Station. The teen, whose name was withheld, was booked on suspicion of murder at the Eastlake Juvenile Hall.

Vernon said both boys had attended a continuation high school class held in a room of the senior center at Angels Plaza, just above the tunnel.

“According to witnesses, both boys were members of rival gangs, and a dispute developed during the school day,” Vernon said. “They took their fight off campus, and squared off in the tunnel.

“Both these kids lived in South Los Angeles and were affiliated with rival Hispanic gangs,” Vernon said. “Their connection to downtown was in attending classes as part of what the Los Angeles Unified School District calls Central High School, which holds classes across the city for at-risk youths.”

Anyone with more information on the case was urged to call Detective Thayer lake, (213) 972-1254, or (877) LAPD-24-7.