Updated 07/01/16 – 2:38 p.m.

CHICAGO (CBS) — Two robbery suspects were killed in a crash in West Pullman following a police chase that started in Tinley Park. Four Chicago police officers and two other robbery suspects also were were injured in the wreck.

An unmarked police vehicle crashed into a home and another vehicle flipped onto its roof in a crash at 124th and Union late Friday morning.

“I thought it was a bomb,” said Michael Wells Sr., whose home was the scene of the impact.

The incident started shortly before 11 a.m., with a robbery in the southwest suburbs. Tinley Park Police Chief Steve Neubauer said suspects confronted the manager of an Arby’s restaurant in the parking lot at 191st and Harlem as the manager was going to the bank for a deposit.

The robbers stole an undetermined amount of cash, and fled the scene. The manager suffered minor injuries in the robbery.

Illinois State Police spotted the suspect vehicle on Interstate 57 and began a chase.

Chicago Police later joined the chase, and the suspect car collided with a police vehicle at 124th and Union, according to Chicago Police Department spokesman Anthony Guglielmi.

The police vehicle apparently caught fire after what First Deputy Supt. John Escalante called a “horrific crash.”

“Police were coming from everywhere. They just speeded up. They were going real fast. By the time we got to Halsted, there was a lot of traffic. So the guys in the gold car, they got up on the sidewalk. At that point in time I think the police should have cut it off,” witness Regina Raines says.

She adds: “They were going at least, 80, 90 a 100 miles an hour. They had the pedal to the metal. They were going. And the police were doing the same.”

Guglielmi said four officers were in the vehicle involved in the crash, and were injured, but in stable condition.

Four suspect were in the other vehicle; two later died. One suspect was pronounced dead at Northwestern Memorial Hospital, the other was pronounced dead at Stroger Hospital. Conditions for the other two suspects were not immediately available, but police said they were in custody.

Illinois State Police are investigating the police pursuit, CBS 2’s Suzanne Le Mignot reports.