A Herndon High School graduate was one of three Marines killed last week in Afghanistan, the Pentagon confirmed Monday. Ryan Jeschke, 31, was a gunnery sergeant who was killed Aug. 10 while conducting a special operations mission in the Helmand Province, according to the Department of Defense. Also killed were Matthew Manoukian, 29, of Los Altos Hills, Calif., and Staff Sgt. Sky Mote, 27, of El Dorado, Calif.

Media reports identify the men as the U.S. Marine Special Operations Forces slain last week by an Afghan police officer in Sangin. The area in the southern part of the country is a former center of anti-government Taliban drug trafficking and roadside bomb manufacturing. The Pentagon did not immediately address the specifics of their deaths but said the "incident is under investigation."

According to reports, accounts of the attack are conflicting. Some say the shooting happened at a police checkpoint while others say it happened on a U.S. military base.