Investigation into Deadly Plane Crash Reveals Possible Hypoxia Connection and Sonic Boom Caught on Camera.

The National Transportation Safety Board (NTSB) is investigating a private plane crash in Virginia that killed all four people onboard. Investigators are considering whether hypoxia, a potentially deadly condition caused by lack of oxygen, is a reason the pilot and passengers didn’t respond to efforts to contact the plane. The aircraft ultimately slammed into a heavily wooded area near Waynesboro, Virginia, and its impact left few recognizable pieces behind. The NTSB plans to begin recovering salvageable pieces of the plane, a Cessna 560 Citation V, on Tuesday.