WASHINGTON — From North Carolina to New Jersey, nearly 1.8 million people still without electricity were asking the same question Monday evening: 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 and knocked out power to 3 million homes and businesses, 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 air-conditioning units were installed in windows 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 held 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.

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

A few backup utility crews arrived Sunday in Maryland, but many didn’t make it until Monday. That’s because the storm arrived so quickly, unlike hurricanes, which typically 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 8½ days to restore power to 750,000 customers after 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.

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, such as 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 Springvale Terrace 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.”

Margaret Foster, 93, and Helen Ofsharick, 95, 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.”