A natural gas distribution expert says the house and building explosions in Lawrence, Andover, and North Andover are "unprecedented".
New England Gas Workers Association President Mark McDonald says over-pressurization of the gas lines could be behind the emergency.
He says a failure in the primary and secondary pressure regulators along distribution lines could have led to the explosions.
The cause of the explosions, which have killed one and injured over a dozen, are still under investigation.
The Governor has already promised a complete investigation and those responsible for the deadly events will be held accountable.
Shelters are available to The Red Cross has also set up reception centers for evacuees at Parthum Elementary and Arlington School in Lawrence and the Andover Cormier Youth Center.
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