Declassification

CIA Debriefed Soviet H-Bomb Eye-Witness in 1957

During the Fall of 1955, a confidential source would later tell U.S. intelligence officials, he had been at work at a soda plant in Kazakhstan when he suddenly experienced a “significant change in pressure on his ear drums,” causing his hearing to go out briefly. According to a CIA report published for the first time by the National Security Archive, the source recalled that the ground began to shake and the workers were ordered out of the plant. Buildings in the area began to oscillate “as if they had been set in motion by the ground.” Moreover, the air was “crackling with pressure;” as if the “air was tearing up.” Then he turned around and saw “the upper third of a large fireball on the southwest horizon,” appearing in “color and intensity like a bright sun shining through a haze.” Realizing that he had witnessed a nuclear test, the source later heard that it had caused several deaths in the area. It is likely that the witness experienced the effects of the Soviet Union’s first test of a two-stage thermonuclear weapon (invented by Andrei Sakharov), air-dropped at Semipalatinsk on 22 November 1955, although he recalled the event as taking place on 8 December 1955.