Middletown, Conn. — Possible gaps in safety protocols at the Kleen Energy power plant are at the center of the investigation into an explosion Sunday that killed five and injured 12.
The blast occurred during the process of purging an underground, high-pressure natural gas pipeline that runs about 800 to 1,000 feet through the facility.
Sources familiar with the purging operation and the construction and maintenance of the pipeline reported several concerns, including that welding operations weren't entirely halted and other ignition sources may have been present during the purging Sunday morning.
The sources added that the area wasn't completely cleared of workers and vehicles during the operation and that natural gas was used to purge the pipe, as opposed to nonflammable nitrogen.
Middletown Deputy Fire Marshal Al Santostefano said the investigation -- being conducted by multiple city, state, and federal agencies, including the U.S. Occupational Safety and Health Administration and the U.S. Chemical Safety and Hazard Investigation Board -- will focus on whether there were other ignition sources present during the purging.
"It's going to try to determine whether all electricity was shut down as a precaution, workers moved from the area -- all of those issues," Santostefano said.
The Chemical Safety Board recently issued safety recommendations concerning purging after investigating a natural gas explosion in June 2009 at the ConAgra Slim Jim production facility in Garner, N.C.
Santostefano said authorities believe many of those on the site at the time of the explosion worked for O&G Industries of Torrington, the general contractor building the plant, which was nearly complete.
William Corvo, a principal partner in the Kleen Energy Project, declined this morning to answer questions about safety protocols or provide details of the purging operation.
"We're focused now on the human side," said Corvo, who was the face of the project in Middletown and in Connecticut during the seven-year process to win permits, capacity contracts and about $1 billion in financing. "We have people who were hurt, people who were killed. We're worried about the families."