Authorities that inspected the cause of the explosion concluded that the explosions came from overpressurized gas lines. The gas company failed to account for crucial pressure sensors while workers were replacing centuries-old cast-iron pipes in the town of Lawrence. By omitting that critical safety step, highly pressurized gas flooded into the area's distribution system at massive levels.
A Columbia Gas-contracted work crew was executing an approved work package to replace the old low-pressure cast-iron distribution system. The old system relied on 14 regulator stations that controlled the gas at the required pressure. Once the old system was disconnected, it began to lose pressure; regulators then responded to the loss of pressure by totally opening, allowing the full force of the gas to rush into the distribution system.
Even though there was a Columbia Gas monitoring center in Columbus, Ohio, that received two high-pressure alarms for the South Lawrence gas pressure system, the workers at that facility had no way to control the pressure by closing or opening valves. They could only advise those in the field, and it only took minutes for the disaster to occur.
The company cut corners, acted in reckless disregard, and violated the federally mandated Pipeline Safety Act resulting in massive damages to property, the displacement of 8,000 residents, 22 severe injuries, dozens of minor injuries, and one teenage fatality.
For months afterward, residents were still uprooted and without service. For many, the explosion was a defining point in their lives, and years later, Merrimack Valley residents worry about their own safety and the safety of their homes. Furthermore, the economic impact for businesses may be felt for years to come from a loss of services performed and sales.