A foot of snow blanketed parts of Michigan and Wisconsin during the night, closing schools Tuesday and causing numerous traffic accidents.

At least three traffic deaths were blamed on the weather in Michigan.

Snow started falling Monday and continued early Tuesday, piling up about a foot deep in western Michigan and up to 13 inches deep in some areas of southeastern Wisconsin. A winter storm warning remained in effect through Tuesday evening in parts of Michigan.

Nearly every school was closed in the Grand Rapids region.

Most highways in the southern two-thirds of Wisconsin were snow-covered and slippery Tuesday, the Wisconsin State Patrol's Web site showed.

Part of Interstate 90 near the Wisconsin-Minnesota state line was closed for about two hours Monday by a pileup on a snow-covered Mississippi River bridge.

Jesse Carlson, who was headed home to Dresbach, Minn., after work in Wisconsin, said he braked to avoid a collision on the I-90 bridge and found himself in the middle of the pileup. "I must have gotten hit four or five times," he said.

Elsewhere, freezing rain on the Plains early Tuesday iced highways in Oklahoma, causing one traffic death and closing schools in parts of the state. One accident shut down Interstate 35 in Oklahoma City for nearly four hours, police said.

"Until we get some sunshine, the roads are going to remain dangerous and we need people to be careful," said Oklahoma Highway Patrol Capt. Chris West.

Schools also were closed Tuesday in parts of northern Kentucky, where snow showers made roads slippery.