“We potentially have two other shooters that we have not located,” Lanier said in a brief news conference outside the gates to the sprawling base.
Lanier confirmed that one shooter had been killed, but said that police were still searching for a white male last seen around 8:35 Monday morning wearing khaki military-style clothes and a beret, carrying a handgun and a black male approximately 50 years old, wearing a military style olive, drab uniform who may have been carrying a rifle.
Witnesses told police that both men were wearing “military style uniforms” Lanier said, but added that they may not actually be members of the military. The investigation is still “very active,” she added, asking residents to stay out of the area and in their homes while police search the area.
Mayor Vincent Gray called the shooting a “horrific tragedy.”
“As far as we know, this is an isolated incident,” Gray added, saying that no other military installations appeared to have been involved.
President Obama, speaking at the White House, praised the victims as “patriots” who “know the dangers of serving abroad” but faced “unimaginable violence they wouldn’t have expected at home.” He promised that federal and local law enforcement officials would work together to investigate the shooting.
The number of casualties remained uncertain. Lanier confirmed “multiple victims inside who are deceased.” Other officials said that at least four victims had been killed and eight wounded in the shooting.
Dr. Janis Orlowski, chief operating officer at MedStar Washington Hospital Center, reported three shooting victims at the hospital but added that they expected to receive more victims.
“From the reports of the victims, it had to be a semiautomatic,” she said. “They’re talking about gun shots that they heard in rapid succession.”
One woman admitted to the hospital had a gunshot wound to head and her hand, another woman had a wound to her shoulder and a male D.C. police officer had multiple gunshot wounds to his legs, Orlowski said.
The three are in critical condition, she said, but described their chances for survival as good.
The incident began at roughly 8:15 a.m. at the headquarters of the Naval Sea Systems Command at the sprawling naval base which flanks Washington’s Anacostia River waterfront. Several witnesses told reporters that the shooting broke out on the fourth floor of the building and that the gunman shot down into the building’s open atrium.
“I think it was all on the fourth floor,” Patricia Ward, one of the witnesses, told reporters.
Ward, a logistics management specialist, was in building 197 when the shooting started. She said she was in the lobby using the ATM machine when she heard three shots. She said she started “panicking.” She said she didn’t know what was going on. Then she heard four more shots. A security guard with a gun drawn told them to run, she said. “I just ran. I thought of my family and I just ran.” Someone had pulled the fire alarm.
Ward said that to get into the building, a person has to scan an ID card and put his or her bags through a metal detector. She added there is no metal detector for the body. She said that may be how the shooters got weapons in.
Roughly two hours later, witnesses at the base reported hearing shots fired. A senior law enforcement official said a gunman, who had been barricaded in a room in the headquarters building, had been shot and killed. The shooter had engaged police in a running firefight, a senior law enforcement official said.
A federal law enforcement official monitoring the situation said the conflicting reports of more than one gunman are coming from a situation where a “second building” is being checked for reports of shots fired. The official said most of the shooting occurred at the Sea Systems Command building, and that tactical SWAT squads were now canvassing the second building.
“We won’t know what we have until we clear that other building,” said the source, who asked not to be identified because of the fluid situation.
Officials have ramped up security in all federal buildings in the Washington area. As a precaution, U.S. Capitol Police have added personnel and increased security measures in the Capitol Building.
As helicopters hovered above the base, first lowering stretchers to airlift victims to local hospitals and later circling the base in an apparent search effort, air traffic was briefly grounded at the nearby Reagan National Airport. Several area schools were put on lockdown.
A D.C. police officer and a base security officer were among the reported victims.
About 3,000 people, both civilian and military, work at the Naval Sea Systems Command Headquarters.
Navy Capt. Danny Hernandez said he was in an adjoining Navy Yard building when the shooting started.
“Everybody rushed in,” to the building where he was, and security guards locked down the facility.
“It was pretty orderly,” he said.
Hernandez said in a cellphone conversation that the lockdown was still in effect.
A White House official reported that President Obama had been briefed on the situation.
[For the Record, 8:33 a.m. PDT Sept. 16: An earlier version of this post incorrectly identified Navy Capt. Danny Hernandez as Navy Capt. Danny Rodriguez.]