WASHINGTON (AP) -- From North Carolina to New Jersey, 2 million people without electricity are asking the same question: Why will it take so long to get the lights back on?

Nearly three full days after a severe summer storm lashed the East Coast, utilities warned that many neighborhoods could remain in the dark for much of the week, if not beyond.

Friday's storm arrived with little warning, so utility companies have had to wait days for extra crews traveling from as far away as Quebec and Oklahoma. And the toppled trees and power lines often entangled broken equipment in debris that must be removed before workers can even get started.

Adding to the urgency of the repairs are the sick and elderly, who are especially vulnerable without air conditioning in the sweltering triple-digit heat. Many sought refuge in hotels or basements.

Officials feared the death toll, already at 22, could climb because of the heat and widespread use of generators, which emit fumes that can be dangerous in enclosed spaces.

At the Springvale Terrace nursing home and senior center in Silver Spring, Md., generators were brought in to provide electricity, and window air conditioners were installed in large common rooms to offer respite from the heat and darkness.

Residents using walkers struggled to navigate doors that were supposed to open automatically. Nurses had to throw out spoiled food, sometimes over the loud objections of residents who insisted their melting ice cream was still good.

The lack of power completely upended many daily routines. Supermarkets struggled to keep groceries from going bad. People on perishable medication called pharmacies to see how long their medicine would keep. In Washington, officials set up collection sites for people to drop off rotting food. Others had weekend cookouts in an attempt to use their food while it lasted. And in West Virginia, National Guard troops handed out food and water and made door-to-door checks.

When it comes to getting the power running again, all utilities take a top-down approach that seeks to get the largest number of people back online as quickly as possible.

First, crews repair substations that send power to thousands of homes and businesses. Next, they fix distribution lines. Last are the transformers that can restore power to a few customers at a time.

In Great Falls, Va., just outside Washington, patent attorney Patrick Muir found out firsthand who was high on the priority list. The area is sparsely populated and wealthy, with mansions spread across secluded, wooded lots. Muir had been raiding water bottles from his powerless office to supply his home, which is on a well that was not working. His 8-year-old daughter spoke hopefully of a beach trip to escape the heat. Dad said it was under consideration.

"Great Falls always seems to be the first to go down and the last one to come back up," Muir said.

A Safeway supermarket trying to stay open with a limited power supply handed out free bags of dry ice. But after two days of temperatures in the 90s, the air inside was stale. Shopping carts with spoiled food, buzzing with flies, sat outside the store.

At a CVS pharmacy, Mahesh Tickle did the best he could. He had no cash register, so he made change with loose bills and coins stuffed inside a Ziploc bag. Tickle filled what prescriptions he could and fielded questions from customers wondering if medications such as insulin had spoiled.

Some people said the destruction over the weekend was reminiscent of that caused by Hurricane Isabel in 2003 and Hurricane Irene in 2011.

Some backup utility crews arrived Sunday in Maryland, but many were not expected until sometime Monday. That's because the storm arrived so quickly, unlike hurricanes, which approach with several days of warning and give out-of-state crews plenty of time to get into place.

After Isabel, it took electricity supplier Pepco eight days to restore power to most of the 500,000-plus customers in Washington and the surrounding areas. About 443,000 lost power at the peak of this storm, and restoration work will likely last into the weekend.

Last year, it took Baltimore Gas and Electric company eight and a half days to restore power to all 750,000 customers who lost power during Hurricane Irene. This time, the power company initially confronted more than 600,000 people without power. It said restoration efforts will extend into the weekend.

BGE said in a letter posted on its website that it would take hundreds of thousands of man-hours to clear debris and work through outages. Crews are working around the clock in 16-hour shifts.

"This type of widespread, extensive damage also complicates our ability to quickly provide accurate restoration times, especially when original damage assessments are revised upon closer inspection of the work required," the letter said.

However, Maryland Gov. Martin O'Malley has been blunt that the utilities must work faster: "No one will have his boot further up Pepco's and BGE's backsides than I will," O'Malley said Sunday.

Pepco spokeswoman Myra Oppel said the differences between storms can be significant. Two storms could have the same number of customers with outages, but the root of the problem could be downed wires in one situation and downed poles in another. But repairing poles takes a lot longer.

As a result, the length of time it takes to restore power "depends on what damage has occurred, not the number of outages," Oppel said.

In the case of Friday night's storms, crews are contending with trees that have to be removed before crews can get to damaged infrastructure.

She said the fact that neighboring states were also hard-hit meant many utilities were competing to get the same backup crews for help.

In Baltimore County, Eveena Felder, a registered nurse, had been relying on air-conditioned public areas to keep cool during the day and a fan to help her family sleep.

"We've purchased a ton of batteries, that's where most of our money has gone," Felder said. "Turn the fan on and keep still, don't move, less energy."

Officials were especially concerned about people in isolated rural areas.

In Greenbrier County, W.Va., "they have no radio station. They have no TV station. They have no communications because without power, they don't have phones," said Lt. Col. David Lester of the West Virginia National Guard.

Back at the nursing home, the cable was out as well, so in the common rooms with generator power the center played movies on old VHS tapes, including the 1932 classic "Grand Hotel."

Ninety-three-year-old Margaret Foster and 95-year-old Helen Ofsharick passed the time outside.

"You wouldn't want to live this way more than a day or so," Foster said. "There are sick people here, or people who don't think too well. They need help."