An investigation Criminal_investigation conducted Action by the United States Environmental Protection Agency ( EPA ) concluded in 1996 that the explosion Attack was initiated Process_start by an accelerated thermal decomposition reaction Response as `` a direct result of unsafe operating Being_in_operation procedures and conditions '' at the plant .

mount vesuvius violently spewed Self_motion forth a deadly cloud of unk tephra and gases to a height of , ejecting Motion molten rock , pulverized Destroying pumice and hot ash at 1.5 million tons per second , ultimately releasing 100,000 times the thermal energy of the unk bombings .