DRESHER — Utility crews struggled to fix a record number of power failures in Pennsylvania as residents returned to jobs and schools in the aftermath of Sandy.

The storm that did so much damage along the coast before spinning inland was blamed for at least 12 deaths in Pennsylvania.On Wednesday, police in Bensalem, Bucks County, said an early morning electrical fire that killed two women was reported only hours after power was restored to the home and is considered storm-related. An 86-year-old man found dead beside a generator in a Berks County garage died of carbon monoxide poisoning, officials said.

Countless homes and cars were damaged by falling trees, but the state largely escaped the major flooding many had feared.

Power outages were the most detrimental byproduct, with 1.2 million Pennsylvania customers in the dark at the peak. The number fell to about 525,000 this morning, but it could take as long as a week before everyone is back on.

Kevin Carlin, who manages the Dreshertown Shop n Bag supermarket in Montgomery County, said Wednesday that his store and about 20 others in the shopping plaza had been without power since Monday night. He used 500 pounds of dry ice to keep food cold until getting a generator truck on Tuesday that has, since then, kept the lights on and the perishables fresh.

Still, the fact that his lights are on caused some false hopes for would-be shoppers, many of whom drove up thinking the store was open. An employee by the door was holding a sign that said “closed” to help break the news. “That’s been the hardest part, turning people away,” Carlin said. “Everybody is pretty understanding.”

Utilities will begin providing repair cost estimates this week, but the total price tag won’t be known until the work is completed, Pennsylvania Public Utility Commission spokeswoman Jennifer Kocher said. The utilities aren’t required to provide estimates to the commission but the totals, when known, will be reviewed when utilities ask for a rate increase to recover those costs, she said.

Customers usually end up footing the bill, but oversight commissions don’t always permit utilities to recoup everything they ask for, said Jay Apt, director of the Electricity Industry Center at Carnegie Mellon University.

He said after devastating hurricanes hit Florida in 2004 and 2005, for example, some of that state’s utilities weren’t fully compensated, though he conceded such an outcome is “a bit unusual.”

The Department of Environmental Protection, which regulates drinking water and wastewater plants, said problems because of flooding or power loss were widespread, particularly in eastern and central Pennsylvania. In some cases, raw sewage was diverted into streams or overflowed from equipment, and authorities issued boil-water advisories.

Some wastewater treatment plants remained inoperable Wednesday, including eight in south-central Pennsylvania. In three northeastern counties — Lackawanna, Luzerne and Monroe — 10 boil water advisories were issued, the agency said.

State officials extended for a week or so the deadlines on inheritance taxes, employer withholding and motor carrier road tax filings and payments with due dates between Oct. 29-31. Also extended are third-quarter unemployment compensation tax filings that had been due Wednesday.

PennDOT gave motorists until Nov. 15 to renew vehicle registrations and safety and emissions inspections due Wednesday. Driver’s license and identification cards that expire between last Friday and Nov. 15 are now due for renewal Nov. 15.