Chicago CNN  — 

A 30-mile stretch of highway in Illinois was closed Thursday after over 100 cars were involved in multiple crashes.

Interstate 39 southbound from Normal to Minonk will be closed for about 12 hours due to the pileup, Illinois State Police tweeted Thursday.

Normal Illinois is part of the Bloomington metropolitan area. Minonk is about 28 miles north of Normal.

“Together, with our local partners, we are diligently working to ensure motorists are safely escorted from the area to warming centers,” ISP said.

ISP urges the public to use extreme caution and only travel if absolutely necessary.

The crash comes as this section of north-central Illinois is experiencing heavy snow and “significantly reduced visibility,” according to the National Weather Service in Lincoln, Illinois.