On the morning of July 2, 1956, an explosion involving scrap thorium occurred at the Sylvania Electric Products' Metallurgical Laboratory in Bayside, Queens, New York. Nine people were injured, some severely. One employee died on August 6, 1956. Workers described three fireballs.
Sylvania was experimenting with large-scale production of thorium metal from thorium dioxide. Part of the process of shutting down this experiment was the reprocessing and burning of thorium metal powder sludges that went unprocessed during the experiment. It was during the incineration of this material that the explosion occurred. At the time the metallurgical properties of thorium were not well understood.
The plant's medical director stated to the press at the time that the employee who died as a result, Oliver Blaber, had succumb to "complications caused by third-degree burns". Blaber's son would later cite the death certificate, which listed "thorium poisoning". The role of radiation was downplayed, especially to assuage fears that a nuclear explosion had occurred. The debris from the explosion was ultimately disposed of in the ocean.