Discuss as:

Immigration agent killed in shootout at federal building in Long Beach

An immigration agent shoots and injures his boss before being killed by another agent. NBC's Thanh Truong reports from Long Beach, Calif.

Updated at 3:03 a.m. ET -- LONG BEACH, Calif. -- Two immigration agents were involved in a shootout at a federal building in Long  Beach Thursday, leaving one dead and another wounded, the FBI said.

The injured officer was taken to a nearby hospital and was listed in stable condition, according to a statement by U.S. Immigration and Customs Enforcement (ICE). The suspected gunman, who was also an ICE agent, was killed by a colleague, the FBI's Steven Martinez told reporters.

Martinez characterized the incident as a case of workplace violence. He said one agent fired several rounds at the other agent, wounding him. At that point, a third agent intervened and additional rounds were fired, resulting in the death of the alleged shooter.


Martinez said the colleague "intervened and fired his weapon to prevent additional rounds being fired at the victim."

The wounded agent was reportedly shot in the upper torso.

Citing multiple law enforcement sources, the Los Angeles Times said the initial shots were fired by an agent at his supervisor during an unspecified dispute.

"At times like this words honestly seem inadequate. When something like this happens in our offices, it's incomprehensible," ICE Special Agent in Charge Claude Arnold said.

The incident occurred around 5:30 p.m. Thursday (8:30 p.m. ET) on the seventh floor of the federal building, located on the city's oceanfront, police said.

ICE issued a statement confirming that two agents from the Homeland Security Investigations division were shot.

KNBC-TV

Police and firefighters respond following a shooting at a federal building in Long Beach, Calif.

The ICE statement said the shooting would be investigated by ICE internal affairs, the Long Beach Police Department and the FBI.

More than a dozen police vehicles and at least two fire trucks lined the sidewalks surrounding the heavily secured building.

In addition to ICE, the nine-story federal building also houses the Internal Revenue Service and the U.S. Probation and Parole Office.

The Associated Press and msnbc.com staff contributed to this report.

More content from msnbc.com and NBC News