LONG BEACH, Calif. (AP) — A federal immigration agent shot and seriously wounded a co-worker during a Thursday evening workplace confrontation before another agent pulled his weapon and shot the gunman to death inside a Southern California federal building, the FBI said.

The Immigration and Customs Enforcement agents were shot on the seventh floor of the Glenn M. Anderson Federal Building in Long Beach, about 20 miles south of downtown Los Angeles.

The 5:54 p.m. Thursday shootings were described by the FBI’s Steven Martinez as a case of “workplace violence involving two federal agents in their office space.” He offered no other details about what led to the initial shooting.

A possible dispute

But the Los Angeles Times, citing multiple law enforcement sources, reported today that the initial shots were fired by an agent at his supervisor during an unspecified dispute.

“Another agent, working nearby, intervened and fired his weapon to prevent additional rounds being fired at the victim,” said Martinez, the assistant director in charge of the FBI’s Los Angeles office.

The gunman died at the scene and the wounded agent was hospitalized at St. Mary’s Medical Center. ICE Special Agent in Charge Claude Arnold would only say he was stable.

St. Mary’s hospital trauma director James Murray told KCAL- TV that the injured agent had multiple gunshot wounds, but he didn’t give details. The victim’s vital signs were “ good for now,” Murray said.

The names of the dead gunman, the victim and the agent who fired the final rounds were not released.