The crash happened in Dearborn County, Indiana, close to the Ohio state line.
Sgt. Stephen Wheeles with the Indiana State Police said there were two separate crashed that totaled 40 different vehicles. The crash scene was a half-mile long.
Many of the vehicles involved were tractor trailers.
Here are some more photos showing the crash scene:
More photos from the accident scene on I-74 in Harrison, OH. pic.twitter.com/twaoAiRsDq
— Brandon Orr (@BrandonOrrWx) January 12, 2016
Sgt. Wheeles posted this photo after the clean-up started:
Crews working to clear I-74 crash near 168 mm. Two crashes involving 40 vehicles total in half mile stretch. pic.twitter.com/UAFbThAPwT
— Sgt. Stephen Wheeles (@ISPVersailles) January 12, 2016
That part of the country was hit by two rounds of snowstorms Tuesday morning, causing slick roads and poor visibility.
WCPO-TV reports there were some serious injuries in the crash.