CHICAGO (CBS) — Four Chicago firefighters and one other person were injured Sunday morning, when a fire engine and a car collided in the Greater Grand Crossing neighborhood.

Fire Department officials said, around 7 a.m., Engine 122 was involved in a crash with a passenger vehicle at 75th and Dr. Martin Luther King Jr. Drive. A CTA bus shelter was demolished in the collision.

Police said the fire engine was headed north on King Drive and its lights and sirens were running when it hit the other vehicle, which was headed east on 75th Street.

Four firefighters were injured in the crash. One was taken to Advocate Christ Medical Center in serious but stable condition, one was taken to University of Chicago Medical Center in serious but stable condition, and two were taken to Little Company of Mary Hospital in fair condition. All but one had been released from the hospital by Sunday afternoon.

The woman who was driving the car was taken to University of Chicago Medical Center in serious but stable condition.

The cause of the crash is under investigation.

Police said the fire engine’s braking system was not working properly. The Fire Department could not confirm that, but said the engine was being examined Sunday afternoon to see if there was a problem.