 The National Transportation Safety Board eventually blamed the blast on the car itself, as a crack had developed when the car was damaged by the derailment.It is believed that this crack expanded when the car was moved off the tracks, eventually causing overpressurization in the tank, causing the single wall to give out.The NTSB commended the town of Waverly on its preparedness for such an emergency, but also exposed the need for all people involved in accident cleanups to be trained in how to handle hazardous materials.