PHOTOS: Several Killed, Up To 10 Wounded On Grounds Of Washington Navy Yard In Southeast D.C. [UPDATED 1:20PM]

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1:20PM (Monday): At least one gunman opened fire inside a building at the Washington Navy Yard on Monday morning, and officials said six people were killed and at least four were wounded, including a law enforcement officer.

Police were looking for two other potential gunmen wearing military-style uniforms, including one who had on a beret, chief Cathy Lanier said.

Authorities have identified the dead shooter as a Navy employee whose work status had been changed earlier this year, said a federal government official who spoke only on condition of anonymity because he wasn’t authorized to speak on the record. While that may suggest the motive was job related, authorities haven’t ruled out anything including terrorism, the official said. Lanier said she didn’t think the other gunmen were part of the military.

Witnesses described a gunman opening fire from the fourth floor, aiming down on people in the first-floor cafeteria. Others said a gunman fired at them in a third-floor hallway. It wasn’t clear whether the witnesses on different floors were describing the same gunman.

As emergency vehicles flooded the streets around the complex, a helicopter hovered overhead, nearby schools were on lockdown and airplanes at nearby Reagan National Airport were briefly grounded so they wouldn’t interfere with law enforcement choppers. Less than 2 miles away, security was beefed up at the U.S. Capitol and other federal buildings, but officials said there was no known threat.

President Barack Obama mourned what he called “yet another mass shooting” in the U.S. that he says took the life of American patriots. Obama promised to make sure “whoever carried out this cowardly act is held responsible.”

Two Navy officials confirmed at least six people had died. The officials spoke on condition of anonymity because they were not authorized to discuss the situation publicly.

About 3,000 people work at the Naval Sea Systems Command headquarters, which builds, buys and maintains the Navy’s ships and submarines and combat systems.

Todd Brundidge, an executive assistant with Navy Sea Systems Command, said he and other co-workers encountered a gunman in a long hallway of their building on the third floor. The gunman was wearing all blue, he said.

“He just turned and started firing,” Brundidge said.

Terrie Durham, an executive assistant with the same agency, said she also saw the gunman firing toward her and Brundidge.

“He aimed high and missed,” she said. “He said nothing. As soon as I realized he was shooting, we just said, ‘Get out of the building.'”

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.

Shortly after the gunfire, Mason said someone on an overhead speaker 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 getting breakfast.

“It was three gunshots straight in a row — pop, pop, pop. Three seconds later, it was pop, pop, pop, pop, pop, so it was like about a total of seven gunshots, and we just started running,” Ward told reporters several blocks away from the Navy Yard.

Ward said security officers started directing people out of the building with guns drawn.

Police and federal agents from multiple law enforcement agencies responded. Ambulances were parked outside, streets in the area were closed and departures from Reagan National Airport were temporarily halted for security reasons.

Janis Orlowski, chief operating officer of Washington Hospital Center, told reporters the hospital was treating three gunshot victims in critical condition. One was Washington, D.C., metropolitan police officer and two were civilian women.

Orlowski said the police officer was in the operating room with gunshot wounds to the legs. A woman had a gunshot wound to the shoulder and the other had gunshot wounds to the head and hand.

District of Columbia schools officials said 12 public and charter schools and one administrative building in the vicinity of the Navy Yard were placed on lockdown. The action was taken out an abundance of caution, schools spokeswoman Melissa Salmanowitz said.

The Homeland Security Department said security was stepped up at federal buildings in Washington as a precaution in the wake of the shooting.

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. Only security personnel were allowed to be armed on the campus.

The Navy Yard has three gates, according to its website. One is open 24/7, and must be used by visitors. A second gate is only for military and civilian Defense Department employees and the other is for bus traffic.

The Navy Yard is part of a fast-growing neighborhood on the banks of the Anacostia River in southeast Washington, just blocks from Nationals Park.

12:00PM (Monday): At least one gunman opened fire inside a building at the Washington Navy Yard on Monday morning, and officials said several people were killed and as many as 10 were wounded, including a law enforcement officer.

A shooter had died, though it wasn’t immediately clear how, according to a Defense Department official and federal law enforcement official who spoke on condition of anonymity because they were not authorized to discuss the matter publicly. Two other officials have said police were looking into the possibility of a second shooter.

Witnesses described a gunman opening fire from the fourth floor, aiming down on people in the first-floor cafeteria. Others said a gunman fired at them in a third-floor hallway.

As witnesses emerged from the building, a helicopter hovered over the building, schools were on lockdown and airplanes at nearby Reagan National Airport were briefly grounded. Less than 2 miles away, security was beefed up at the Capitol, but officials said there was no known threat there. President Barack Obama was getting frequent briefings on the shooting.

The exact number of people killed and the conditions of those wounded was not immediately known. About 3,000 people work at the Naval Sea Systems Command headquarters, which builds, buys and maintains the Navy’s ships and submarines and combat systems.

“He just turned and started firing,” Brundidge said.

Terrie Durham, an executive assistant with the same agency, said she also saw the gunman firing toward her and Brundidge.

“He aimed high and missed,” she said. “He said nothing. As soon as I realized he was shooting, we just said, ‘Get out of the building.’”

Shortly after the gunfire, Mason said someone on an overhead speaker 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.

“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.

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 with a person onto the roof.

Officials at MedStar Washington Hospital Center said two shooting victims had been brought there.

District of Columbia schools officials said six schools and one administrative building in the vicinity of the Navy Yard were placed on lockdown. The action was taken out an abundance of caution, schools spokeswoman Melissa Salmanowitz said.

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.

The Navy Yard is part of a fast-growing neighborhood on the banks of the Anacostia River in southeast Washington, just blocks from Nationals Park and about 1 ½ miles southeast of the U.S. Capitol.

11:05AM (Monday): A gunman opened fire inside a building at the Washington Navy Yard on Monday morning, and a Defense Department official said several people were killed and as many as 10 were wounded, including at least one law enforcement officer.

A shooter was “contained” but not yet in custody, according to the official, who spoke on condition of anonymity because they were not authorized to discuss the matter publicly. 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.

The exact number of people killed and the conditions of those wounded was not immediately known.

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.

10:45AM (Monday): President Barack Obama is getting frequent briefings on a deadly shooting at the Washington Navy Yard.

The White House says the president had several briefings about the unfolding situation by senior aides.

The Navy says shots were fired Monday morning at the Naval Sea Systems Command headquarters, where about 3,000 people work. A defense official confirms that several people were killed and as many as 10 others were wounded.

The official also says the shooter is “contained” but not yet in custody.

The Navy said in a statement that the active shooter was reported inside the building at 8:20 a.m. A “shelter in place” has been ordered for Navy yard personnel.

The White House says Obama directed his team to stay in touch with the Navy, FBI and local officials.

10:03AM (Monday): Several people were injured in a shooting Monday morning at a building at the Washington Navy Yard, the U.S. Navy said, and authorities searched for an active shooter.

A defense official, who spoke to The Associated Press on condition of anonymity because he was not authorized to speak during an active attack, also said there were at least several injuries.

The Navy said shots were fired around 8:20 a.m. at the Naval Sea Systems Command headquarters, where about 3,000 people work.

The number of the victims and their conditions was not immediately known, though the Navy said multiple people had been injured.

Police and federal agents from multiple law enforcement agencies responded to the scene. Ambulances were parked outside, streets in the area were closed and flights at Reagan National Airport were temporarily halted.

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.