State legislators and regulators moved yesterday to question utilities about the power outages that persist for tens of thousands of Marylanders nearly a week after Tropical Storm Isabel tore through the region.

Virtually all schools and roads that were closed in Isabel's wake are open this morning. But 73,000 customers of the region's two major power suppliers - Baltimore Gas and Electric Co. and Potomac Electric Power Co. - were without electricity last night.

Del. Dereck E. Davis, chairman of a committee that has oversight over the utilities, said he wants an explanation of what caused the widespread outages and why it took so long to restore power.

"I understand this was not a conventional storm," said Davis, a Prince George's County Democrat who heads the House Economic Matters Committee. "I'm not bringing the utilities in to beat them up."

The Maryland Public Service Commission announced it will start its own investigation into the utilities' response to Isabel and to power losses from a series of August thunderstorms.

Gov. Robert L. Ehrlich Jr. believes the inquiries "will be appropriate and helpful," said his spokesman Henry Fawell.

"The governor does appreciate the efforts the utility companies have made," Fawell said. "We've literally seen lives lost; it's not easy for them. He will continue to both help them, and hold their feet to the fire, to meet his number one goal of seeing electricity restored."

Spokesman Robert L. Gould said BGE is sticking to its target of late Friday for restoring power to all customers - except some in flooded-out areas.

The work is tougher now, Gould said. Earlier this week, BGE could bring large blocks of customers back on line with one or a few repairs; now each outage presents a unique problem. "We're in the house-to-house combat mode."

Gould also said that BGE "will continue to work cooperatively with the PSC, to thoroughly assess our response efforts. We are confident that the PSC will be well-satisfied with BGE's preparedness and response during this restoration effort."

Spokesman Tom Welle said Pepco "welcomes" reviews by any legislative or oversight agency. "We are a regulated entity and that's part of doing business, to expect reviews or this kind of scrutiny."

Government aid

Meanwhile, government officials stepped up efforts yesterday to help storm victims. Baltimore County Executive James T. Smith Jr. announced that owners of storm-damaged homes and businesses in the county will get property tax rebates in the coming weeks.

State law allows for reassessments when a home or business is destroyed, but the owner ordinarily needs to request it. In this case, state assessors and Baltimore County inspectors will examine damaged structures within the next week, and the county will send refund checks a few weeks after that.

"Residents shouldn't have to study the Maryland code to realize what is owed to them in an emergency," Smith said.

By yesterday afternoon, more than 1,700 storm victims in Baltimore County alone had signed up for assistance from the Federal Emergency Management Agency, and hundreds more took advantage of food and water distribution centers.

Other attempts by the county government to help were less popular - few people had shown up for free showers at three east-side schools as of yesterday evening.

Anne Arundel County Executive Janet S. Owens announced that a team of workers will visit homeowners to offer damage assessments, advice on repairs, insurance counseling and other services.

And as a result of the federal declaration of emergency in Maryland, residents who lost their jobs because of the storm - but who would otherwise be ineligible - can claim unemployment benefits, the Maryland Department of Labor, Licensing and Regulation said.