By Vi Nguyen

CHICAGO (CBS) — The search is on for a driver who led police on a chase in the western suburbs before crashing his car, hitting and killing a 60-year-old man.

The victim’s family says they had no idea police were pursuing another car when the crash happened. Now, they want an explanation from the police department.

A memorial marks the spot where Suos Khloth was killed early Sunday morning in Joliet. The 60-year-old was involved in the Cambodian community and worked at a local church for years.

Khloth had just picked up his nephew and they were heading home east on Jefferson Street. They were hit by another car Crest Hill police had been pursuing.

“We’re going to miss him a lot because nothing be the same,” Som Khloth, the victim’s son said. “Nobody know he died until the next morning. Most of his friends are devastated he’s gone so fast.”

Cell phone video taken by a witness shows the aftermath of the deadly crash.

Crest Hill police say an officer tried to stop a Mitsubishi Endeavor for a speeding violation in the area of Theodore and Edgerton, but the car took off.

The officer chased the car into Joliet.

It’s unclear how fast they were going, but just moments after hitting Khloth’s car, the driver of the Mitsubishi ran away and his passenger was taken into custody.

“I wish they could handle better for us to have closure or the suspect caught,” Som Khloth said. “No one said anything.”

The department is investigating whether the officer followed pursuit policy. As for the driver who got away, investigators are following up on leads.