A gunman later identified as Aaron Alexis, 34 a Navy vet of Texas went on a shooting massacre killing 12 people at the Navy Yard's Naval Sea Systems Command Headquarters in Southeast Washington D.C. around 8:00 a.m. today. At this time it is unclear whether Alexis was working alone. However, Alexis was shot and killed by police. reportedly, D. C. Police said as many as 2 additional gunmen wearing military-style uniforms may still be at large and thousands of workers at the building were told to "shelter in place" until officials could safely evacuate them.
""This is not over. The building is still in lock-down, as are other buildings. Still being treated as an active search. No one is moving right now."
- Rear Admiral John Kirby, U.S. Navy chief spokesman
D.C. Mayor Vincent Gray said investigators had not identified a motive for the shooting. There was no indication that the incident was an act of terrorism, he said. According to several witnesses who managed to escape, they described at least one of the shooters as a tall, black man with an AR-15 assault rifle.
"They sounded like 'pop, pop, pop. Everybody just panicked at first ... It was just people running, running, running. I just kept running. Our mission is to take care of the Navy ... After today, it's not secure enough for me."
Patricia Ward, a logistics management specialist who was in the cafeteria.
Police sources earlier told The Washington Post that as many as 3 shooters, including one in military fatigues, were involved in the mass shooting. The police received the first 9-1-1 call around 8:15 a.m. Officers were on scene within minutes. A police officer was also shot and killed. There was a white male suspect who was later cleared. Hours after police responded, authorities continued to search for suspects, and low-flying helicopters were spotted circling above the scene, dropping baskets to evacuate people from the complex.
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. Mason said the gunman was aiming down at people in the building's cafeteria on the first floor, adding that 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. People who were inside the building said a gunman wordlessly sprayed fire from an AR-15 assault rifle as terrified civilians and Navy members scattered.
"We saw him holding the rifle and then we saw him aim it in our direction"
-- unidentified witness who told FoxNews reporters
"We were looking, but he was down the hall far enough that we couldn't see a face. But we saw him hold the rifle and then we saw him raise it and aim in our direction."
-- unidentified witness
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.
Out of an abundance of caution, U.S. Capitol Police will conduct enhanced security operations on the Capitol Complex, although no known threat exists. Eight nearby schools were also reportedly locked down as a precautionary measure.
White House officials, in a statement released shortly after the shooting, confirmed that President Obama had been briefed on the incident. More than 20 members of the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) responded to the scene, including the same Special Response Team that extracted the alleged Boston Marathon bomber Dzhokhar Tsarnaev from the boat where he barricaded himself following the April 15 attack.