 Upon receiving a report of the supposed attack, NORAD went on high alert.However, doubts about the authenticity of the attack arose due to the presence of Soviet leader Nikita Khrushchev in New York City as head of the USSR's United Nations delegation.On 24 January 1961, a B-52 Stratofortress carrying two 3–4-megaton Mark 39 nuclear bombs broke up in mid-air near Goldsboro, North Carolina, dropping its nuclear payload in the process.