At least 18 die from exposure and car crashes as fierce storm brings rain and snow across much of the US.

A fierce winter storm has knocked out power to hundreds of thousands of homes and businesses across the United States and left at least 18 people dead due to exposure and car crashes on icy roads.

The “bomb cyclone” storm, one of the most powerful in decades, also forced the cancellation of more than 3,000 US flights on Saturday, stranding thousands of travellers who were making last-minute dashes for Christmas.

(Al Jazeera)

The storm, now in its third straight day, was nearly unprecedented in its scope, stretching from the Great Lakes near Canada to the Rio Grande along the border with Mexico. The plummeting temperatures brought the coldest Christmas Eve on record to some parts of the country, including in Washington, DC.

Power systems across the US were under strain due to rising demand for heat and storm-related damage to transmission lines.

According to tracking site, at least 300,000 homes and businesses were without power as of Saturday evening, a sharp drop from 1.8 million customers who were without power earlier in the day.

But many electric companies continued to ask people to conserve energy by not running large appliances and turning off unneeded lights.

Across the country, officials attributed at least 18 deaths to the effects of the storm, including two people who died in their homes outside the city of Buffalo in New York state when emergency crews could not reach them amid historic blizzard conditions.

Erie County Executive Mark Poloncarz said a third person had also died in Buffalo and that the blizzard may be “the worst storm in our community’s history”.

It was taking ambulances over three hours to make one trip to hospital in areas where a vehicle could get through the snow, he said, adding that there were “hundreds of people still stuck in their vehicles”.

He added that the National Guard was being sent “right into the city of Buffalo for these life-threatening rescues”.

New York Governor Kathy Hochul meanwhile said almost every fire truck in Buffalo was stranded due to the snow. “No matter how many emergency vehicles we have, they cannot get through the conditions as we speak,” she said.

Other storm-related deaths include four people killed in the state of Ohio on Friday during a pileup involving some 50 vehicles. In Missouri, a driver was killed on Thursday after skidding into a creek, while in Kansas, three others died on Wednesday in separate crashes on icy roads.

A utility worker was killed in Ohio on Friday while trying to restore power, while a woman in Vermont died in hospital on the same day when a tree broke in the high winds and fell on her. In Colorado, police found the dead body of a person who appeared to be homeless as subzero temperatures and snow descended on the region. In Michigan, a snowplough driver found an 82-year-old woman curled up in the snow outside of her assisted living community. She was pronounced dead later.

Three deaths were also reported in Kentucky, where Governor Andy Beshear on Saturday warned residents, “Stay home, stay safe, stay alive.”

“I know it’s really hard because it’s Christmas Eve. But we’re having dozens and dozens of accidents,” he said in an online briefing. “It’s simply not safe.”

Along Interstate 71 in Kentucky, Terry Henderson and her husband, Rick, told The Associated Press news agency that they were stuck in a massive traffic jam caused by several accidents for 34 hours. The truck drivers weathered the wait in a rig outfitted with a diesel heater, a toilet and a refrigerator but nonetheless regretted trying to drive from Alabama to their home near Akron, Ohio, for Christmas.

“I wish we should have stayed,” said Terry Henderson, after they got moving again Saturday. “We should have sat.”

The severe weather also forced the cancellations of some 3,411 flights within, into or out of the US on Saturday, according to the tracking site FlightAware. While in Mexico, refugees and migrants camped near the US border in unusually cold temperatures as they awaited a US Supreme Court decision on pandemic-era restrictions that prevent many from seeking asylum.

The National Weather Service said its map of existing or impending meteorological hazards “depicts one of the greatest extents of winter weather warnings and advisories ever”.

In hard-hit Buffalo, Latricia Stroud said she and her two daughters, 1 and 12, have been stranded without heat or power in their house since Friday afternoon, with the snow too deep to leave.

“I have to go over a snowbank to get out,” Stroud told AP. “There’s a warming center, I just need a ride to get there.”