According to Moore, a preliminary investigation by the Bureau of Alcohol, Tobacco and Firearms' National Response Team found that the bomb squad significantly underestimated, based on a visual assessment, the weight of explosive material that was being loaded into the bomb squad truck for detonation.
The truck -- which has been used 41 previous times over the last decade, including for three detonations in June -- can safely contain the detonation of up to 15 pounds of explosive materials for repeated use or up to 25 pounds for one-time use that would render the truck out-of-service in the future. Bomb technicians followed department protocols to limit handling of the explosive devices and estimated the total amount of explosive material being loaded into the truck was 16.5 pounds, Moore said. The National Response Team's physical weighing of the materials found that the actual amount was 42 pounds.