I-Team: Columbia Gas Has History Of Serious Incidents

BOSTON (CBS) - Investigators have zeroed in on the potential cause of the gas fires in the Merrimack Valley: Over pressurization of a gas main owned by Columbia Gas.

Bob Ackley of Safe Gas USA says, "If the cause is mechanical we can fix that if it is human error we can put safeguards in place to prevent it from happening again. This was a monumental tragedy."

Hours before the explosions, Lawrence Police posted a photo of gas line work in the area. Earlier the company notified customers in the Merrimack Valley that crews would be upgrading the equipment and released a video showing how the work would be done.

It wasn't long after that when police began getting reports of explosions and fires and gas experts say even though the fires are out, the situation is still very dangerous. Ackley said he wouldn't consider homes and businesses safe until utility crews checked to be sure no gas was inside.

The I-Team has learned that Columbia Gas has a history of problems. From 1986 to 2012, the company has been involved in 13 serious incidents that resulted in two fatalities and 32 injuries and millions of dollars in damage.

The most recent 2012 explosions in Springfield, the fire marshal said, was caused by human error. In many of those incidents, the Massachusetts Department of Public Utilities found safety violations and fined the company tens of thousands of dollars.

Ackley says Friday's fires and explosions could have been a lot worse. "Luck, probably prevented a lot of houses from not going up," he said. In those cases, the pilot lights on appliances, furnaces and water heaters blew out and the electricity got shut off so nothing caught fire.

Columbia Gas is part of NiSource one of the largest utility companies in the country. While the NTSB is leading the investigation, several other state and federal agencies are also involved.