Investigations found Know failure to ensure secure storage of the radiation source to be the root cause of the accident , which resulted in Causation ten people being hospitalized Institutionalization for radiation injury , three of whom died Death , as well as the potentially significant exposure of 1,872 people .

Investigations conducted Action by the Department of Justice ruled out Removing deliberate criminal activity in 2013 .

Investigations by Occupational Safety and Health Administration ( OSHA ) and the Bureau of Alcohol , Tobacco , Firearms and Explosives also concluded Coming_to_believe that sugar dust was the fuel for an explosion Catastrophe that could have been prevented Preventing_or_letting .