At least 12 people have been killed in the Washington Navy Yard shooting, according to D.C. Mayor Vincent Gray, CNN reports. One suspect is dead, but two others may be on the loose, said Washington Police Chief Cathy Lanier. "The big concern for us right now is that we potentially have two other shooters that we have not located at this point," Lanier said hours after the shooting. Authorities are looking for a white man and a black man in military-style clothing who could be connected to the shooting, she said. "We have no information to believe that either of those folks are military personnel, but we do have information that those individuals are wearing military-style uniforms," she said. Who opened fire at the headquarters for Naval Sea Systems Command -- and why -- remains unclear. "We still don't know all the facts. But we do know that several people have been shot and some have been killed," President Barack Obama said Monday afternoon. "So we are confronting yet another mass shooting. And today it happened on a military installation in our nation's capital." Obama called the shooting a "cowardly act" that targeted military and civilians serving their country.
The violence started unfolding at 8:20 a.m. when several shots were fired inside the headquarters for Naval Sea Systems Command in southeast Washington. Two witnesses told CNN affiliate WJLA-TV they heard a fire alarm go off in the building where they worked, then saw a man with a rifle down the hallway as they exited the building. "He aimed the gun and fired our way," witness Todd Brundidge told WJLA, adding, "I couldn't believe it." People frantically tried to run out of the building, Brundidge said. "Everyone was going down the stairs. They were pushing. They were shoving. People were falling down. As we came outside, people were climbing the wall trying to get over the wall to get out. ... It was just crazy."
Emergency personnel, the FBI, U.S. Capitol Police and local D.C. police responded to the shooting, shutting down traffic in the area on the District's south side along the Anacostia River. Some people were evacuated, and others sheltered in place. At least eight schools were on lockdown as a precaution, the Washington public schools said. Air traffic to Reagan National Airport in northern Virginia, the closest airport to downtown Washington, was suspended but later resumed, the Federal Aviation Administration said.