[Click here to see photos from the scene]

UPDATE: 4:42 (Washington, DC) -- Washington, DC Mayor Vincent Gray is calling the deadly mass shooting at the DC Navy Yard this morning a "horrific tragedy." Gray said police are still looking for another suspect to determine if he was involved in the shooting that left at least 13 people dead. Gray said terrorism is not suspected, but hasn't been ruled out. Gray said no one should be in the area of the Navy Yard until law enforcement officials give the all-clear.

Names of the victims are not being released at this time. Police Chief Cathy Lanier called the crime scene "active." An FBI official says the man who opened fire at the DC Navy Yard this morning was 34-year-old civilian contractor Aaron Alexis. The "Washington Post" says Alexis had an assault rifle and a handgun in his possession when he opened fire.

UPDATE: 3:27 PM (Washington, DC) -- The Fort Worth man suspected to be the person responsible for the mass shooting at the Washington Navy Yard has a criminal past. Aaron Alexis was arrested in 2010 by Fort Worth police for firing a weapon within city limits. Tarrant County prosecutors never filed charges against Alexis. Authorities don't know why the 34-year-old allegedly opened fire on the Navy Yard. Police are looking for another suspect.

UPDATE 3:08 PM(Washington, DC)  --  The suspected shooter in the Washington Navy Yard is a civilian contractor from Texas.  Multiple reports say Aaron Alexis of Fort Worth has been identified as the man who killed at least 12 people and injured more this morning.  No motive has been released and police are looking for another suspect. 

UPDATE: 2:19 PM (Washington, DC)  --  Washington, DC Mayor Vincent Gray says at least 12 people are dead in a Navy facility shooting today.  At least one shooter was killed, but police are still working to determine if there were others involved.  DC Police Chief Cathy Lanier says they're still working to find a motive.  It's believed two other possible gunmen are on the loose.  An active search is ongoing for additional shooters who were dressed in military-style uniforms.  Lanier says it's too early to determine whether the shooters are members of the military.  

The Navy Yard remains on lockdown with a roughly two-mile perimeter set up around the property.  Several people are reported injured.   

UPDATE: 12:29 PM
(Washington, DC)  --  Washington, DC Mayor Vincent Gray says officials are still trying to determine how many fatalities are the result of a mass shooting this morning at the massive U.S. Navy Yard.  Police Chief Cathy Lanier says one shooter is dead, and multiple people were killed.  Lanier says there may be two additional shooters "out there" who have not been taken into custody.  One is a white male, and another is a black male.  Lanier says both potential shooters are wearing military-style uniforms, but they're not part of the military.

UPDATE 12:08 PM(Washington, DC)  --  CBS News is reporting at least six people are dead in the shooting rampage at the Washington, DC Navy Yard.  Three have been taken to MedStar Washington Medical Center with severe injuries, but they're expected to pull through.  A Navy official says at least one shooter is dead.  There were reports of a second shooter. 

UPDATE: (Washington, DC)  --  Two suspects are reportedly "down" in this morning's mass shooting at a Washington, DC Naval facility.  The "Washington Post" reports they've been killed along with four victims in the gunfire.  At least eight people are wounded.  There had been previous conflicting reports on the number of suspects.  Nearby schools are on lockdown.  

Original Story:

(Washington, DC)  --  Several injuries are confirmed in a shooting at the massive U.S. Navy Yard in Washington, DC.  A statement from the Navy notes "reports of fatalities.  The "Washington Post" reports two of the victims are police officers.  Toughly three thousand people who work at the sweeping facility continue sheltering in place as police scour the area for a male gunman.  The shooting occurred at the facility's Naval Sea Systems Command headquarters.  There is a massive law enforcement response including Washington, DC police and the FBI.  A wide area around the base has been cordoned off in southeast Washington. 

President Obama is getting regular briefings on the incident from his chief homeland security adviser and a deputy chief of staff.  The Navy Yard houses the Naval Sea Systems Command headquarters, which is involved in overseeing the engineering, purchasing, building and maintenance of ships, submarines and combat systems.    

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