The pilot of a private jet that caused chaos over Washington DC before crashing likely suffered from hypoxia in the moments before it plummeted to the ground, it has been suggested by an expert.
The US Capitol was briefly put on "elevated" alert after the Cessna Citation entered Washington airspace before crashing into the rocky mountains of Montebello, Virginia.
An Air Force F-16 caused panic after being "cleared supersonic to respond", according to the North American Aerospace Defense Command (NORAD), which sparked an enormous sonic boom heard by residents in both states.
