OMAHA, Neb. - Holiday travelers battled slick, icy roads and scattered flight cancellations and delays yesterday as a major winter storm began to spread across much of the nation's midsection - and the worst of the weather was still to come.

Slippery roads were blamed for at least five deaths - three in accidents on Interstate 80 in Nebraska and two in a crash on Interstate 70 in Kansas.

The storm was likely to intensify by today, bringing heavy snow, sleet, and rain to a large swath of the Plains and the Midwest. A foot or two of snow was possible in some areas by Christmas Day.

"It's an usually large storm, even for the Plains," said Scott Whitmore, a National Weather Service meteorologist in Topeka, Kan.

Holidays travelers and commuters alike were stranded in the Northeast yesterday after an electrical problem forced Amtrak to halt trains in and out of New York's Penn Station. The outage affected service as far south as Washington and as far north as Boston.

Power was restored after about three hours.

Philadelphia's 30th Street Station was crowded with holiday travelers at 4:30 p.m., and outside, cars were backed up angling for the limited parking spaces.

The board above the information area announced: "Due to Power Problems, all trains are delayed." The 3:32 Acela from Boston by one hour. Others by only 15 or 20 minutes.

Philadelphia was the second-to-last stop on the holiday trip for Libby Wachter. Wachter, 30, who lives in Los Angeles, was in the city for a few days visiting her in-laws before heading to Boston to spend Christmas with her family. At 4:35 p.m., she picked up her 7-month-old daughter, Saylor, who had been getting fussy in the stroller.

She had heard that her train was delayed by two hours, so she waited before coming to 30th Street Station. All day, she and her sister, Jesse Lawson, checked in with a friend who was in New York's Penn Station, watching the arrival and departure board.

"Our train was supposed to leave two minutes ago," she said, rocking her baby, dressed in red snowflake pajamas and a hat with floppy bunny ears. "They said it was delayed by 15 minutes. Wait. It just changed. Now it says 25 minutes."

Lawson, who lives in New York, had come to Philadelphia on Sunday, catching one of the few trains to make it through the snowstorm.

"I got really lucky on Sunday," Lawson said. "We're not as lucky today."

Kariyma Wise, a 24-year-old nurse, and her boyfriend, Raynaldo Scarlett, a 27-year-old graduate student, arrived at 4:30 p.m. to discover that their 5 o'clock train to Hartford, Conn., was not even listed on the board yet.

"I knew about the delays from watching CNBC," said Scarlett, who is studying engineering at the University of Pennsylvania and has not been home to see his family in Connecticut in seven months. He came for a 5 p.m. train but was hopeful at 6:45 that he would finally board.