CHICAGO (CBS) — Three people were taken to the hospital Friday morning, after a Pace bus crashed on the Stevenson Expressway.

Illinois State Police said the bus was driving on the left shoulder of the northbound lanes of the Stevenson, when it crashed with two other vehicles near Harlem Avenue, around 6:30 a.m. Pace express buses are allowed to drive on the shoulder during rush hour.

Police said there were 35 people on the bus at the time of the crash.

Three people were taken to MacNeal Hospital in Berwyn, with minor injuries. It was not immediately clear if all of the people who were hurt were on the bus.