QUANTICO, Va. -- A Marine who worked at the corps' officer candidates school fatally shot two of his colleagues before killing himself in a barracks dorm room.
The three Marines -- two men and a woman -- were on the staff at the school on the sprawling Marine Corps Base Quantico in northern Virginia. Officials said the gunman and two victims were members of the same unit and knew one another, The Washington Post reported.
Military officials described the shootings as "isolated." They did not release a motive or the identities of those slain.
Around 10:30 p.m. Thursday, authorities found one Marine dead in the Taylor Hall barracks, base commander Col. David W. Maxwell said. A second victim and the gunman were also located in the building.
Only Marines who work at the school live in Taylor Hall. The officer candidates live elsewhere on the base.
Officials did not say what the three Marines did at the school, which is known for its grueling 10-week program that evaluates candidates on physical stamina, intelligence and leadership. The candidates must complete obstacle courses, hikes of up to 12 miles in full combat gear and take classes on navigation and tactics that help them lead in the field, according to the school's website.
The shooting came days after seven members of the 2nd Marine Expeditionary Force were killed when a mortar shell exploded in its firing tube during an exercise at Hawthorne Army Depot in Nevada. Eight others were injured.
Maxwell made reference to the Nevada deaths in his remarks, choking up as he told reporters that chaplains at Quantico would be providing counseling for Marines and their families.
"I want to express my sincere condolences to the families, friends and fellow Marines of the three Marines we lost last night," Maxwell said. "Our thoughts and prayers are with them at this time. This is a tragic loss for our Marine Corps family." Maxwell said he anticipates a "lengthy investigation" and did not expect the identities of the shooter or the victims to be released until at least Saturday.