Several passengers of a Pace bus were seen being taken off the vehicle on stretchers on Friday morning after a collision involving two other vehicles.
The crash happened on the inbound lanes of Interstate 55 -- the Stevenson Expressway -- at 1st Avenue just after 7:30 a.m.
Pace buses use the shoulder along the Stevenson as part of a program expanded earlier this year due to high demand from riders.
Three people from inside the bus were transported to MacNeal Hospital with minor injuries, an official with the Illinois State Police said.
The accident was cleared as of 8:45 a.m., but officials said they didn't yet know what caused the crash.