WASHINGTON (AP) -- A gunman opened fire inside a building at the Washington Navy Yard on Monday morning, and killed at least 12 people. Several others were wounded, including at least one law enforcement officer.
--CBS's Stephanie Lambidakis says the Navy Yard shooter has been identified as a civilian Navy employee who had some kind of job issues earlier this year. His job status had changed.
Helicopters swarmed overhead, schools were on lockdown and airplanes at nearby Reagan National Airport were grounded as authorities swarmed the area in southeast D.C., just miles from the Capitol.
About 3,000 people work at the Naval Sea Systems Command headquarters.
Emergency personnel respond to a reported shooting at the Washington Navy Yard Monday
Rick Mason, a program management analyst who is a civilian with the U.S. Navy, said a gunman was shooting from a fourth floor overlook in the hallway outside his office. He said the gunman was aiming down at people in the building's cafeteria on the first floor. Mason said he could hear the shots but could not see a gunman.
Shortly after the gunfire, Mason said overhead speakers told workers to seek shelter and later to head for the gates at the complex.
Patricia Ward, a logistics management specialist, said she was in the cafeteria and heard shots. They sounded like "pop, pop, pop," she said. After a few seconds, there were more shots, she said.
"Everybody just panicked at first," she said. "It was just people running, running, running."
Ward said security officers started directing people out of the building with guns drawn.
Police and federal agents from multiple law enforcement agencies responded to the scene. Ambulances were parked outside, streets in the area were closed and departures from Reagan National Airport were temporarily halted for security reasons.
Among the wounded was a D.C. police officer, according to a law enforcement official who spoke on the condition of anonymity because the person was not authorized to discuss an ongoing investigation.
A U.S. Park Police helicopter hovered over the building and appeared to drop a basket or a stretcher with a person onto the roof.
Naval Sea Systems Command is the largest of the Navy's five system commands and accounts for a quarter of the Navy's entire budget. It builds, buys and maintains the Navy's ships and submarines and their combat systems.