(Snapshot from YouTube)

One shooter was killed by law enforcement officials in a building at the Navy Yard two hours after the incident at about 10:30 a.m. local time. Officials are searching for a possible second shooter, there are conflicting reports about the number of shooters. 

"I was walking to the metro around 8:45 and heard a ton of police cars," said D.C. resident Erin Dick, who was on her way to work five minutes after the shooting started.

"I got to the metro I saw a man surrounded by people giving him CPR. The police came and started roping off M street and then I left. I didn't know that it was more than just that one man at the time," said Dick.

Dick, who lives two blocks away from where the shooting took place, was unsure if the man getting CPR was related to the shooting but was surprised by the intense police response. 

"I got the work and saw the news that it was actually a larger shooting inside the navy yard compound," she said.

Employees who had been evacuated from the building described a chaotic situation as an individual armed with a rifle roamed the hallways shooting at people, reported the New York Times. 

The number of victims is still preliminary as authorities are clearing the Naval Sea Systems headquarters at the Navy Yard room by room. About 3,000 people work at the Naval Sea Systems Command headquarters, just miles from the Capitol. 

Security at the Capitol has been enhanced and several schools were put on lockdown, according to local media reports. 

President Obama has been briefed on the situation, according to a White House official. 

“The president directed his team to stay in touch with our federal partners, including the Navy and F.B.I., as well as the local officials,” a White House statement said. “We urge citizens to listen to the authorities and follow directions from the first responders on site.”

Read more at the New York Times.

Reach Executive Producer Syuzanna Petrosyan here. Follow her on Twitter.