The National Transportation Safety Board (NTSB) immediately launched an investigation to what caused the initial derailment and the subsequent explosion. The investigation took almost a full year to complete, and the following paragraph summarizes their finding regarding the cause of this tragedy:
"The National Transportation Safety Board determines that the probable cause of the loss of life and substantial property damage was the release and ignition of liquefied petroleum gas from a tank car rupture. The rupture resulted from stress propagation of a crack which may have developed during movement of the car for transfer of product or from increased pressure within the tank. The original crack was caused by mechanical damage during a derailment, which resulted from a broken high-carbon wheel on the 17th car which had overheated."
[Taken from NTSB-RAR-79-1, dated February 8, 1979]
The total estimated property damage (in 1979 dollars) was set at $1,800,000.00. The explosion destroyed over a dozen buildings in the town and seriously damaged another 20.
The NTSB investigators also commended the Town of Waverly for its emergency plan preparation and the coordination of the emergency response that ensued following the explosion. The report also, however, pointed out that there was a serious need for training of all persons who respond to accidents involving hazardous materials.