NASHVILLE, Tenn. — A lack of oxygen that incapacitated the pilot and three passengers is likely what caused a private jet to become unresponsive before flying over the nation’s capital and prompting the military to scramble fighter jets in 2023, according to a final report from the National Transportation Safety Board released on Tuesday. The oxygen problem was likely caused by a loss of cabin pressure, according to the report. Investigators could not determine the exact reason for the pressure