OMAHA, Neb. —  A winter storm marched across the Plains, causing numerous accidents that killed at least eight people in three states, including four in Nebraska.

Heavy snow hit parts of Nebraska on Saturday, limiting visibility and creating hazardous driving conditions.

A car slid across the median on Interstate 80 near Kearney in central Nebraska and was struck by a tractor-trailer, killing the car's 28-year-old driver and her two children, ages 5 and 3, police said.

On U.S. 281 south of St. Paul, a 76-year-old man was killed when the car he was in crossed the center line and was struck by a pickup. The man's 59-year-old wife was seriously injured.

In western Kansas, a couple and their 20-month-old daughter died when their car drove off U.S. 50 and collided with two others cars, authorities said. The couple's 6-year-old daughter was critically injured, they said.

In Oklahoma, a 5-year-old boy died after being thrown from a sport utility vehicle that veered off a snow-covered highway and rolled.

Up to 6 inches of snow were forecast for some sections of Kansas on Sunday, with more to follow.

Farther south, the storm spared much of Oklahoma, though snow fell in western and north-central regions. The Oklahoma Corporation Commission reported Saturday night that about 36,000 customers in the state remained without power a week after a crippling ice storm.