A New Hampshire woman on oxygen therapy died after the power to her home was cut off, forcing electricity supplier National Grid to defend its policies Friday, the Boston Globe reported.

National Grid supplies electricity and gas to millions of customers in Massachusetts, New Hampshire, upstate New York and Rhode Island.

A worker for the company went to the woman's home in Salem, N.H., on Monday and shut off the power after seeing no sign that anyone was there, company spokesman David Graves told The Globe.

About an hour later police called the company, informing them there had been a medical emergency in the house.

The woman, Kay Phaneuf, 53, died Thursday at the Holy Family Hospital in Methuen, Mass., where she had been in critical condition since being found unconscious by her husband.

Both the state Public Utilities Commission and Salem police are investigating, The Union Leader reported.

By state law, power can not be shut off to homes that rely on it for medical reasons, but the order must be updated every 60 days.

It is believed the account at the home had not been paid, and the emergency certification not renewed.

Graves said he could not comment specifically on why the power was shut off, but the residence had been notified in writing that service was to be terminated.