D.C. and Navy officials said no injuries or evidence of gunshots were found, after a report of possible gunshots at the Navy Yard in southeast Washington, D.C., brought troves of law enforcement to the area Thursday morning.
"There are no signs of a shooting, a shooter, or victims," the Navy said in a statement.
The location had previously dealt with an active shooter situation in September 2013 when Aaron Alexis, a 34-year-old civilian contractor, fatally shot 12 people at the headquarters of the Naval Sea Systems Command. Alexis was killed during a firefight with police.
On Thursday, D.C. Mayor Muriel Bowser said Navy Yard officials asked police for assistance after they received a call at 7:29 a.m. from a Navy Yard employee who said she might have heard gunshots at the facility. The Navy Yard went into lockdown with an order for people to shelter in place. That order was lifted around noon.
"We had a clear, convincing response to the scene," Bowser said.
Scene outside Navy Yard right now. pic.twitter.com/R5tgIsTCgo
— David Jones (@DavidJones2898) July 2, 2015
D.C. Police Chief Cathy Lanier said the response went "very smoothly" and was "well-coordinated."
"It appears that all the things we tried to correct and make better from the last incident went very, very well," she said. "This turned out to be a great exercise for us."
Lanier said Thursday that they took the caller who reported gunshots seriously and did not believe it was a hoax.
"We have interviewed the person and we have no concerns whatsoever," she said. She declined to say whether the employee was in the Navy Yard during the 2013 shooting there.
Law enforcement closed the surrounding streets and searched Building 197, the site of a 2013 mass shooting, before giving the all-clear.
"Once we started going through the building... we took all the employees to a separate building and started interviewing them," Lanier said. "Every inch of that building has been searched."
"It was... like the first time -- a lot of people running for the exits," a Navy Yard employee told ABC7 News Thursday.
Neal Augenstein of WTOP radio posted this video from the scene:
D.C. Police tweeted that the mayor's office is offering counseling resources for Navy Yard employees and residents of the area. Those seeking assistance should call 866-962-5048 or 888-7WE-HELP.
Responding to a question about the Navy security footage from Thursday morning that reportedly showed two individuals jumping a fence near the building just minutes before the call, Lanier said, "We have pulled all video. We are reviewing all video. We have no concerns about it."
Reports of a man on the roof of a nearby government building raised concerns as the Navy Yard was being cleared, but it turned out he was a U.S. Department of Transportation maintenance worker, WUSA9 said.
Laura Barron-Lopez contributed reporting.