(CNN) -- Three people were killed Thursday in a 30-vehicle pileup on Interstate 94 in northern Indiana during whiteout conditions, according to state police.
More than 20 people were sent to area hospitals, including one person with life-threatening injuries, according to Sgt. Ann Wojas of Indiana State Police.
LaPorte County was experiencing heavy snow and extreme cold and winds.
Police said half of the vehicles were tractor-trailers.
Police Lt. Pete Wood said it could take 12 to 24 hours until things get back to normal on I-94. Motorists were urged to find alternative routes.
CNN's Carma Hassan contributed to this report.
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