(CNN) - A shooting prompted an hours-long lockdown at Marine Corps Base Quantico in Virginia.
Authorities say it ended with three people dead, including the shooter. A sergeant says one person was fatally shot, with the shooter barricaded in a room.
Using a PA system, police announced a base lockdown, and police from the base and Prince William County surrounded the area.
The sergeant says when they finally entered the building, they found a second victim dead.
They also found the shooter dead of a self-inflicted gunshot wound.
A Marine spokesman says the suspect was a staff member at the Officer Candidate School.
The motive is unknown.