After being forced out of their homes for two days, residents of Andover, North Andover, and Lawrence, Massachusetts, were told they could return to their homes Sunday morning, but were warned not to turn their gas back on at this time. Governor Charlie Baker said homes throughout the areas impacted by the blasts were cleared of gas by 6:30 a.m. Sunday. The evacuation was prompted by three spontaneous explosions that caused fire or other damage to about 80 homes.
NBC News reports that the source of the explosions was initially unknown, but has now been identified. The pipelines that set off the explosions belong to Columbia Gas of Massachusetts. The National Transportation Safety Board is conducting an investigation into the series of events that led to the dangerous situation including their record-keeping practices and its daily operations. An examination of recent consumer complaints will also be conducted.
In the wake of the explosions that set dozens of homes ablaze, killed one, and injured 25, officials report that almost 8,600 gas meters were turned off. The deceased has been identified as 18-year-old Leonel Robson of Lawrence. He died when a house explosion sent a chimney into the air and onto the car he was sitting in.
Fourteen regulators throughout the area receive gas at 75 PSI and reduce outgoing pressure to.5 PSI. Incoming gas flow has to remain high in order to avoid outages. If a sensor attached to a regulator finds that pressure has dropped too low, more gas is released to compensate. Robert Sumwalt, chairman of the NTSB, said that they believe they have determined the source of the explosion — a pressure sensor that was attached to a gas line that had been capped and removed from service the day of the explosions. This caused a “significantly greater flow-rate and pressure” into homes, triggering the explosions.
Thursday’s explosions forced the closure of schools in all three cities. Schools in Andover and North Andover expect to open again Monday morning, but Lawrence schools will remain closed because gas and electricity have not yet been fully restored. At least a dozen families in Lawrence have been permanently displaced. Mayor Daniela Rivera announced that a relief fund for Lawrence residents affected by the leak has been established and had raised about $100,000 as of Sunday morning.
The CEO of NiSource, parent company of Columbia Gas of Massachusetts, said it will take full responsibility of all findings of the NTSB.