BOSTON (AP) — The Latest on natural gas explosions in Massachusetts (all times local):

11:45 a.m.

The president of the utility that serves the three Massachusetts communities affected by a series of natural gas fires and explosions says the company is donating $10 million to a relief fund.

Columbia Gas President Stephen Bryant made the announcement Tuesday at a news conference attended by Gov. Charlie Baker and leaders of Lawrence, Andover and North Andover.

The Republican governor said the Greater Lawrence Disaster Relief Fund will help residents of the three communities with food, housing and other immediate needs as they recover from last Thursday's fires that killed one and injured two dozen others.

Lawrence Mayor Dan Rivera, who has been highly critical of Columbia Gas, said the utility is "living up to their corporate responsibility" with the donation.

The cause remains under investigation, but early reports indicate over-pressurized gas lines are to blame.

FILE – In this Sept. 13, 2018, file photo, firefighters battle a house fire on Herrick Road in North Andover, Mass., one of multiple emergency crews responding to a series of gas explosions and fires triggered by a problem with a gas line that feeds homes in several communities north of Boston. The pressure in natural gas pipelines prior to a series of explosions and fires in Massachusetts last week was 12 times higher than it should have been. The information was in a letter from the state’s U.S. senators to the heads of Columbia Gas and NiSource. (AP Photo/Mary Schwalm, File)

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7:35 a.m.

The pressure in natural gas pipelines prior to a series of explosions and fires in Massachusetts last week was 12 times higher than it should have been.

The information was in a letter from the state's U.S. senators to the heads of Columbia Gas, the company that serves the communities of Lawrence, Andover and North Andover, and NiSource, the parent company of Columbia Gas.

Democratic Sens. Elizabeth Warren and Edward Markey sent the letter Monday seeking answers to questions about the explosions.

The letter says that according to the Pipeline and Hazardous Materials Safety Administration, "the pressure in the system should have been around 0.5 pounds per square inch, but readings in the area reached at least 6 PSI."

The explosions and fires killed one person and injured more than two dozen.

Source: The Associated Press