PHILADELPHIA — Commuters faced slick roads Friday after yet another winter storm brought snow and ice to the East Coast, leaving at least 24 people dead, including a pregnant woman struck by a mini-plow in New York City whose baby was then born by cesarean section and two Good Samaritans killed when they tried to aid a truck driver on a snow-covered interstate in North Carolina.

The latest go-round of bad weather began overnight in some places — just in time to delay tens of thousands of deliveries of Valentine’s Day flowers — as snow, sleet and rain fell on roads already covered in many parts of the Northeast with deep puddles and icy patches.

Alexander Baez, 24, spent two hours digging out his car before navigating snow-covered roads to his job as a judicial marshal. “It will be a long, slow commute,” Baez said as he filled his tank at a gas station in East Hartford, Conn. “I can’t wait until the summer comes.”

Numerous traffic accidents involving multiple tractor-trailers and dozens of cars completely blocked one side of the Pennsylvania Turnpike outside Philadelphia on Friday morning and injured more than a dozen people. The crashes were reported about five hours after a storm that dropped a foot of snow finally moved out. Speed restrictions imposed during the storm had been lifted, but motorists say the roadway was very slick.

By the time it stopped falling, 22.5 inches of snow was reported in Somerset County, Pa. Parts of upstate New York got between 12 and 27 inches of snow.

The sloppy mix of snow and face-stinging sleet grounded more than 6,500 flights nationwide on Thursday and closed schools, businesses and government centers. About 1.2 million utility customers lost power as the storm moved from the South through the Northeast, dropping to about 465,000 outages by Friday morning, mostly in South Carolina and Georgia.

“Every time it snows, it’s like, “Oh, not again,”‘ said Randal DeIvernois of New Cumberland, Pa., which had about 10 inches of snow by midafternoon Thursday. “I didn’t get this much snow when I lived in Colorado.”

By Friday morning, the number of flight cancellations dropped to about 1,300 nationwide. Many schools remained closed in Connecticut, Maine, Massachusetts, New Hampshire, New York state, Pennsylvania, Vermont and Virginia, while some in Rhode Island were opening late.

The treacherous weather was blamed for nearly two dozen deaths, many of them in motor vehicle accidents.

In North Carolina, two people were killed Thursday night when they tried to help the driver of tractor-trailer cab that spun out on a snow-covered Interstate 40 near Garner. Another driver faces second-degree murder and other charges in the hit-and-run wreck, the state Highway Patrol said.

In New York, 36-year-old Min Lin died after she was struck by a utility vehicle with a snowplow attached to it as it backed up outside a shopping center in Brooklyn. She was rushed by paramedics to a medical center, where her nearly full term, 6-pound, 6-ounce baby was delivered via cesarean section, hospital spokeswoman Eileen Tynion said.

The baby was in critical condition in the neonatal intensive care unit, she said.

No immediate charges were brought against the snowplow operator.

The snow, sleet and ice that bombarded the Southeast on Wednesday brought its ferocity into the Northeast a day later.

Washington, D.C., received 9 inches of snow Thursday, Westminster, Md., reported 19 inches, and Newark, Del., had 14 inches. New York City received nearly 10 inches, and parts of New Jersey had more than 11.

In New York, the teachers union and TV weatherman Al Roker harshly criticized Mayor Bill de Blasio’s decision Thursday to keep schools open. Roker, who was in Russia for the Winter Olympics but has a daughter in New York’s public schools, said on Twitter: “It’s going to take some kid or kids getting hurt before this goofball policy gets changed.”

He largely stood by his criticism on Friday but apologized on NBC’s “Today” show for a tweet forecasting “one term” for de Blasio, saying that was “below the line.”

The mayor said many parents depend on schools to watch over their children while they are at work and keeping the schools open was the right decision.

Across the South, the storm left in its wake a world of ice-encrusted trees and driveways and snapped branches and power lines.

In South Carolina, about 242,000 homes and businesses were without power Friday morning, and officials warned it could be next week before it is restored for everyone. Gov. Nikki Haley planned to visit Aiken and Walterboro to look at some of the most heavily damaged areas.

Nationwide, this is shaping up as one of the snowiest winters on record. As of early this month, Washington, Detroit, Boston, Chicago, New York and St. Louis had gotten roughly two or three times as much snow as they normally receive at this point in the season.

The latest round of bad weather threatened to disrupt Friday deliveries of flowers for Valentine’s Day.

“This storm could not have been worse for us,” said Donna Mahair, owner of the Petal Patch flower shop in Newport, N.H., where more than a foot of snow fell. “All the schools are closed so all the deliveries that were going to the schools, we now have to track down the people they were going to.”

Mahair had to call her niece to plow enough spots for three delivery vehicles. Her shop floor was wall-to-wall vases, boxes and bouquets.

“It looks like Cupid threw up,” deliveryman Brad Palmer said.

Other businesses expected a bounce from the snow.

At Bob Skinner’s Ski and Sport near the Mount Sunapee ski area, owner Frank MacConnell was overjoyed.

“There’s never too much snow,” he said. Sales and rentals are “off the charts” and MacConnell said the storm is a perfect prelude to the traditionally lucrative President’s Week holiday next week.

Scolforo reported from Lemoyne, Pa. Associated Press writers Michael Melia in East Hartford, Conn., Lynne Tuohy in Newbury, N.H.; Kevin Begos in Pittsburgh; Michael Rubinkam in Berks County, Pa.; Kathy Matheson in Philadelphia; Sarah Brumfield and Brett Zongker in Washington; Matthew Barakat in Falls Church, Va.; David Dishneau in Frederick, Md.; and Jeffrey Collins in Columbia, S.C., contributed to this report.