Catherine Thompson

Catherine Thompson is a news writer for Talking Points Memo. Before joining TPM, she worked as a research assistant to investigative reporter Wayne Barrett and interned at The L Magazine. At New York University she served as the deputy managing editor of NYU's student newspaper, The Washington Square News. She can be reached at catherine@talkingpointsmemo.com.

Articles by Catherine

Two workers at the Washington, DC Naval Yard told NBC News on Monday that they encountered a gunman who reportedly killed at least four people and injured at least 10 others in a hallway when he silently raised his gun and opened fire on them.

Terrie Durham and Todd Brundivge, civilian co-workers at the Office of Naval Sea System Command, said they were about 40 yards from the gunman but were able to see that he was dressed in blue and carrying a weapon.

"He was a tall man, appeared to have dark skin, looked like he was in some kind of uniform and he had a rifle," Durham told NBC, adding that the stairwell she was standing in was dimly lit and it was difficult to see the gunman's face.

"No words. He raised the gun and started firing," Brundvige recounted. "He said nothing."

The gunman opened fire on Durham and Brundvige, but aimed too high and missed.

"We're lucky he was far enough away he was a bad shot," Durham said.

This post has been updated.

Washington, D.C. Mayor Vincent Gray called a shooting situation Monday morning at the Navy Yard an "isolated incident." Gray said in a press conference that a shooter entered building 197 at Naval Sea Systems Command (NAVSEA) headquarters at approximately 8:20 a.m., was removed from the scene and then taken to the hospital.

Navy Secretary Ray Mabus tweeted his reactions to the shooting situation at the Washington, DC Navy yard Monday morning and assured he had "complete confidence" in first responders at the scene.

A Navy official said at least four people were killed and several wounded during a shooting situation Monday morning at the Washington, DC Navy Yard, according to the Los Angeles Times.

Navy spokesperson Lt. Courtney Hilson told the Times that the number of victims was "preliminary" as authorities were still moving room by room through the Naval Sea Systems Command (NAVSEA) headquarters.

The Associated Press reported "several people were killed" and as many as 10 were injured, citing a Defense Department official. Earlier, police said at least 10 people were shot.

The U.S. Navy said Monday morning that there were "reports of fatalities" in the ongoing shooting situation at the Washington, DC Navy Yard. The Navy also confirmed that several people were injured.

The Washington Post reported that at least 10 people were shot.

President Barack Obama has been briefed on the "unfolding situation" Monday morning at the Washington, DC Navy Yard, a White House official said.

"The President has been briefed several times about the unfolding situation at the Washington Navy Yard by Assistant to the President for Homeland Security and Counterterrorism Lisa Monaco and Deputy Chief of Staff Alyssa Mastromonaco," the official said, according to a media pool report. "The President directed his team to stay in touch with our federal partners, including the Navy and FBI, as well as the local officials. We urge citizens to listen to the authorities and follow directions from the first responders on site."

Correction: Alyssa Mastromonaco's name was misspelled in a statement, quoted by the pool report, from a White House official on the situation at the Washington, DC Navy Yard.

The Federal Aviation Administration grounded all flights at Ronald Reagan Washington National Airport (DCA) Monday morning, CBS News reported.

An "active shooter" situation was ongoing in the area of the Washington, DC Navy Yard.

The Federal Aviation Administration posted the following notice on its website regarding DCA:

Due to OTHER / SECURITY, there is a Traffic Management Program in effect for traffic arriving Ronald Reagan Washington National Airport, Washington, DC (DCA). To see if you may be affected, select your departure airport and check "Delays by Destination".

Seven people were injured in a shooting Monday morning at the Washington, DC Navy Yard, including a D.C. police officer and a federal officer, NBC's Pete Williams reported. Williams cautioned that number may change as more information becomes available.

The U.S. Navy confirmed "several injured" in the shooting.

A police spokesman confirmed to the Washington Post that a Washington, D.C. police officer was among at least three to four people who were shot Monday morning at the Navy Yard there.

The spokesman told the Post that the officer was shot near a room in Navy Sea System Command's (NAVSEA) headquarters, where a lone gunman barricaded himself after allegedly shooting at least three people on Navy Yard grounds.

The U.S. Navy has so far only confirmed that one individual has been injured.

One person has been confirmed injured in an "active shooter" situation at the Washington, DC Navy Yard Monday morning. Watch live coverage of the ongoing situation below.