Investigation into Virginia Plane Crash Continues with Hypoxia as Potential Factor.

A Cessna Citation business jet crashed into a remote Virginia mountain, killing all four people aboard. The pilot was not responding to air traffic control instructions and the situation was soon reported to a network that includes military, security and law enforcement agencies. The plane took an erratic flight path, prompting the military to scramble fighter jets. Outside aviation experts continued to speculate that the pilot likely lost consciousness from a lack of oxygen inside the jet when it climbed above 10,000 feet. The investigation is ongoing.