CHICAGO — A crash early Sunday morning involving a Cook County Sheriff’s squad car on the Dan Ryan Expressway is under investigation and reportedly sent two sheriff’s officers to an area hospital in serious condition.

Multiple lanes were shut down early Sunday morning, but all lanes have since reopened.

The crash happened at about 4:15 a.m. Sunday in the southbound lanes of the Dan Ryan Expressway, near the 95th Street CTA station.

Spokespeople for the Chicago Fire Department and the Cook County Sheriff’s Office told WGN News that paramedics took five people to area hospitals in the crash that involved four total vehicles.

Two of those hospitalized were sheriff’s officers, and they were reported to be in serious condition. The three others were civilians, one reported to be in serious condition and two reported to be in fair condition.

According to preliminary information from Illinois State Police, troopers responded to a four-vehicle accident, including the Cook County Sheriff’s squad car. ISP says it’s still trying to determine the chain of events that led to the crash and the circumstances surrounding it.

The squad car could be observed with back-end damage at the scene of the crash.

WGN News has reached out to the Cook County Sheriff’s Office for an update on the condition of the two officers taken to the hospital in serious condition and is awaiting a response.

The damaged vehicles and wreckage from the crash had been removed from the Dan Ryan Expressway before 7 a.m. Sunday.