At least 10 wounded in Washington Navy Yard shooting; multiple fatalities

The Washington Navy Yard was placed on lockdown after multiple shots were fired inside a building on the base, the U.S. Navy said.

At least 10 people were injured in the shooting, including eight civilians, one Washington, D.C., Metro police officer and one base officer, D.C. Metro Police said. There were several fatalities, according to the Associated Press.

The Navy said three shots were fired at the Naval Sea Systems Command Headquarters building on the base at approximately 8:20 a.m., and police were treating it as an active shooter situation. According to the Washington Post, the officer was shot near the room where a lone gunman had barricaded himself.

Rick Mason, administrative specialist program management specialist for the U.S. Navy, told Yahoo News he was on the fourth floor when he saw a shooter had a shotgun, aiming down into the atrium. The gunman, Mason said, was targeting people who walked into the cafeteria.

A "shelter in place" order was issued for Navy Yard personnel, the Navy said in a news release.

Approximately 3,000 people work in the building where the shots were heard, though it's unclear how many people were inside at the time of the shooting.

A heavy SWAT and police presence could be seen around the Navy Yard, and a helicopter was circling overhead.

Employees could be seen huddled outside the base crying and holding each other.

According to WJLA-TV, a "ground stop" was ordered at Reagan National Airport, and schools in the area were placed on temporary lockdown, and several roads were closed in the area.

A White House official said President Barack Obama has been briefed several times about the unfolding situation at the Navy Yard by Assistant to the President for Homeland Security and Counterterrorism Lisa Monaco and Deputy Chief of Staff Alyssa Mastromanaco.

The Navy relayed news of the shooting via Twitter: