Investigation
A full investigation was launched into the accident by several government agencies, as well as legal representatives for the families of the deceased. The investigation determined that the leak was initially discovered by employees of the contractor J.M. Brennan Inc., who helped maintain plumbing, heating, air conditioning and ventilation equipment at the plant. These four employees noticed propane gas pooling as Falk employees started the propane system, which the factory uses as a backup fuel supply when natural gas is shut down during peak demand. These employees alerted other workers to the problem. There had been testing conducted on the system for a full 40 minutes prior to the explosion. It is also thought the leak came from an underground pipe that ran from propane tanks to the propane/air mixers, which convert the liquid propane into gaseous form, so that it is in a form usable by the boilers. This is backed up by the discovery of a small pocket of gas trapped below asphalt directly below the Annex building. Pressure testing of the pipe using nitrogen has since confirmed it was leaking. Subsequent excavation showed it had two separate leaks; Metallurgists have examined the damaged sections of pipeline and determined that the pipe corroded. Falk's evacuation procedure will also feature prominently in the investigation.
Based on one persons account, Rexnord accused J.M. Brennan employees of discouraging the evacuation. J.M. Brennan has adamantly denied this. Although they did not design it or install the entire system, J.M. Brennan acknowledged they installed parts of the system, including the pipeline, across 1962-1963. The case settled out of court. Falk also had a fatal explosion in 1964 which killed one person and damaged a car almost a mile from ground zero. Attorney Robert Habush, representing the families, says the line was installed by Brennan, in 1988.
Read more about this topic: 2006 Falk Corporation Explosion