In aerodynamics, pitch-up is a severe form of stall in an aircraft, at transonic speeds the aerodynamic loads can become so high as to break up the aircraft, as occurred in 1964 when which type of supersonic fighter-bomber, used by the United States Air Force Thunderbirds broke up in mid-air?
Pitch-up:  Unlike conventional low-speed stalls, pitch-up can occur at any speed, and are especially dangerous when they take place in the transonic; at these speeds the aerodynamic loads can become so high as to break up the aircraft, as occurred in 1964 when a F-105 Thunderchief of the USAF Thunderbirds broke up in mid-air. Republic F-105 Thunderchief: The Republic F-105 Thunderchief was a supersonic fighter-bomber used by the United States Air Force.
Republic F-105 Thunderchief