CALEDONIA -- The Special Investigation Unit is investigating a crash that left two people, including an OPP officer, with serious injuries.

The crash happened near Caledonia on Haldimand Road 9 on Tuesday evening.

Officials said the cruiser collided head-on with a red truck, which flipped onto the cruiser.

"It was a mess, it was dark," said Gary Webster, who lives nearby. "You couldn't really see what was going on other than the one truck that was upside down and fire rescue trying to get him out."

The officer was trapped and had to be freed from his vehicle. He was airlifted to Hamilton General Hospital.

Webster said he saw the flashing lights from his home and rushed to the scene.

"The fire rescue were trying to open the door, to get the person out of the red truck, which was upside down," Webster said. "He was trapped, whoever was trapped inside."

Police said the driver of the pickup truck was also taken to hospital with serious injuries.

"OPP thoughts are with the Norfolk County OPP officer in hospital," the OPP Association said on social media. "Injuries are not life-threatening."

The driver of the truck was arrested for impaired driving, but CTV News confirmed no charges had been filed at Cayuga's courthouse on Wednesday afternoon.

Webster said the stretch of road where the crash occurred is a problem area.

"We have witnessed several near misses," he said.

The SIU said two investigators and two forensic investigators have been assigned to the case.

The OPP declined to comment as the SIU completes the investigation.

With files from