It was caused by the explosion of seven army ammunition trucks loaded with 1053 boxes of dynamite, which were parked in Cali overnight.
Hypotheses at the time for the explosion include trucks overheating or a soldier accidentally firing his gun.
[clarification needed] He said of the incident: "the mushroom cloud left by the explosion resembled that formed by the atomic bombings of Hiroshima and Nagasaki, but smaller in proportion ... mutilated body parts including legs, arms, torsos could be seen.
Following the tragedy, local Colombian organizations such as the Red Cross, the Sendas organization (Department of Social Welfare and Child Protection, later the Colombian Institute of Family Welfare (Instituto Colombiano de Bienestar Familiar), the Boy Scouts and the Sisters of Charity and clergy offered help.
The Holy See, then headed by Pope Pius XII, the Soviet Union, the Kingdom of Afghanistan, the Pahlavi dynasty of Iran (Persia), Vietnam, the Kingdom of Laos, the Philippines, North Korea, the United States, Canada, Mexico, Venezuela, the Mongolian People's Republic, South Korea, Japan, China and Europe sympathised with the victims.