Police: No evidence of shooting at Washington Navy Yard

Police say there was no evidence of a shooting at the Washington Navy Yard Thursday morning after a report of gunshots triggered a large scale response by multiple law enforcement agencies.

Police say they received a call from a female employee in a building inside the campus at around 7:30 a.m. The caller told police that she may have heard gunshots.

Officers swarmed the Washington Navy Yard and placed the complex on lockdown while the reports were investigated and buildings were searched.

"The folks that were evacuated out of 197, the Humphreys Building, based upon the location of the building, they either went outside of the Navy Yard or they went over to our conference center," said Vice Admiral Dixon Smith, commander of the Navy Installations Command.

D.C. Police Chief Cathy Lanier said within 20 minutes, she was in a command center with military and federal officials monitoring the situation.

"Metropolitan Police Department officers and FBI were able to get into and take control of the command booth and access everything we needed in terms of cameras," said Lanier.

Despite the massive response, no shooter was found and no one was injured. An all-clear was given around 10:30 a.m. and workers were allowed back into the building shortly afterwards.

"What often happens with a response of this nature is there is a lot of police activity going on in the neighborhood and people's sense of alertness is heightened and when they see different things going on, they will call, which again, we ask people to call," Lanier said. "So we started getting additional calls about people on roofs and a lot of what we were getting was people calling in what they saw and police response."

D.C. Police Chief Cathy Lanier said they spoke to the woman who made the initial call to police and do not believe her report to be a hoax.

"The person who made the call heard what she thought may have been gunshots and she made a call, which is what employees here are trained to do," she said.

Lanier said the response went smoothly and was well-coordinated. She said as more officers interviewed employees who were inside the building, the more confident investigators were that no shots were ever fired inside the Humphreys Building.

On September 16, 2013, gunman Aaron Alexis shot and killed 12 people at the headquarters of the Naval Sea Systems Command inside the Washington Navy Yard before he was fatally shot by police. The building has since been renamed the Humphreys Building. It reopened this year.

D.C. Mayor Muriel Bowser came to the scene and said the response was justified based on lessons learned.

"We have found that there has been a clear, coordinated and convincing response to this scene," said Bowser. "We are grateful at this point that we have found no shooter, evidence of shooting or any victims."

As a response to that incident almost two years ago, many of the response protocols that were used in Thursday's alert were put into place.

Here is a breakdown of the timeline of events from this morning's incident:

UPDATE - 11:11 a.m.
Mayor Muriel Bowser and Police Chief Cathy Lanier say a call for possible gunshots prompted the Thursday morning response to the Washington Navy Yard. The city leaders say that agencies, including D.C. Police, FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives responded and gave the all clear around 10:30 a.m. No evidence of any shooting was found.

UPDATE - 10:16 a.m.
DC POLICE: A call was placed from a building inside of the Washington Navy yard for possible sounds of gun shots around 0729 AM - a subsequent request was made to partner law enforcement agencies for assistance. At this time we have completed our search of the building and have found no evidence of a shooting or injured personnel. The scene has been turned back over to Vice Admiral Hilarides of the NavSea Command.

UPDATE - 10 a.m.
FBI: All clear at Washington Navy Yard campus.

UPDATE - 9:42 a.m.
Police activity reported near 300 M Street, SE. Some road closures remain.

UPDATE - 9:25 a.m.
US Navy Yard Police say no shots fired - no injuries - no reports of a shooter - no victims have been found - police are still searching the building.

UPDATE - 9:08 a.m.
Initial information of suspected shooters came from security guards who reported the information to police. Police have not yet cleared the building. Police have not found any shooters or victims.

UPDATE - 8:55 a.m.
No shooters found inside building after reports of 2 shooters on second floor of building 197. Police continue to search buildings in Navy Yard complex.

UPDATE - 8:48 a.m.
DC Police close roads M St SE from S. Capitol to 11th St SE/11th St from M St to Virginia/.

UPDATE - 8:42 a.m.
Lt. Commander speaks to FOX 5 and says he was in building 197 - sheltered until escorted out by police.

UPDATE - 8:35 a.m.
FOX 5's sources report 2 possible shooters seen inside building - 1 black male - 1 white male - armed, inside building - one victim.

UPDATE - 8:31 a.m.
US Navy tweets order to lock down/shelter in place.

UPDATE - 8:27 a.m.
Police are inside building 197 searching for possible gunman - possible victim. This is the same building as the 2013 shooting.

UPDATE - 8 a.m.
The Navy Yard, and locations around the area on M Street, are on lock down.

FOX 5's Assignment Manager Doug Buchanan says multiple sources confirm that there was a shooting at the location just after 7:30 a.m.

FOX News reports that an employee inside the Washington Navy Yard reports that alarms are sounding inside the buildings.

The Associated Press contributed to this report.