Google is my friend. J'ai peut-être trouvé un truc.
\"10 November 1950: A B-50 Superfortress was ferrying a Mk 4 atomic weapon from Canada to a base in the United States when it suffered engine trouble. Fearing they could not make an emergency landing while carrying the heavy weapon, the crew jettisoned the bomb over the St. Lawrence River off the shore of Quebec. The weapon was set to self-destruct and detonated in mid-air. A plutonium core was not installed but the explosion scattered some 100 lb (45 kg) of depleted uranium across the river below.\"
http://www.aerospaceweb.org/question/we ... 0268.shtml
Pour information le B-50 est un B-29 remotorisé (60% plus puissant selon wikipedia).