Yesterday afternoon, a massive explosion at an under-construction Connecticut power plant killed five workers and wounded several more. Workers at the Kleen Energy plant in Middletown, CT were reportedly purging a natural gas line, and the explosion was so powerful that residents towns away reported hearing it and feeling tremors. About 100 firefighters worked for an hour to extinguish the blaze and then begin searching for survivors, local station WFSB reports.

The Hartford Courant gives the names of two of the five workers killed: Pipefitters Ronald Crabb, 42, of Colchester, and Raymond E. Dobratz, 58, of Old Saybrook. Twenty-six victims were also treated for injuries, and five of them remain hospitalized.

The Chemical Safety Board reports that it’s deploying a seven-person investigative team to the explosion site. Their news release also contains this very relevant piece of information:

At a public meeting on Thursday, February 4, the CSB issued urgent recommendations that the national fuel gas codes be changed to improve safety when gas pipes are being purged – cleared of air – during maintenance or the installation of new piping. The Board’s urgent recommendations resulted from the CSB’s ongoing federal investigation into the June 9, 2009, natural gas explosion at the ConAgra Slim Jim production facility in Garner, North Carolina, which caused four deaths, three critical life-threatening burn injuries, and other injuries that sent a total of 67 people to the hospital.

The CSB issued a safety bulletin on gas purging in October 2009, because of the occurrence of multiple serious accidents during purging operations.  Key safety lessons described in the bulletin included purging gases to a safe location outdoors away from ignition sources, evacuating non-essential workers during purging, using combustible gas monitors to detect any hazardous gas accumulations, and effective training for personnel involved in purging.

The CSB’s recommendations sound sensible. We’ll have to wait for the results of their investigation in Middletown to learn whether the Kleen Energy plant was taking these steps – or whether they could have prevented this workplace tragedy.