The driver of a tractor trailer that crashed in Ancaster Monday was killed by blunt force trauma brought on in the wreck, an autopsy has revealed.

Police originally believed a medical emergency caused the crash, and now are back at square one and searching for the reason why the 61-year-old driver crashed on Monday morning. Speed and alcohol have been ruled out as contributing factors, police say.

"It's still ongoing," Police spokesperson Debbie McGreal-Dinning said Tuesday.

The incident happened around 6:20 a.m., when a fully-loaded 53-foot Canada Cartridge tractor-trailer was going westbound on the Linc. The driver exited at Mohawk Road/Golf Links Road, but then the truck went straight off the ramp and flipped over onto the grassy embankment between the off and on ramps, police say.

The driver was pronounced dead at the scene. “Numerous pieces of heavy equipment were required to assist in gaining access to the driver,” a police press release reads.

The coroner, the police reconstruction unit and officials from the Ministry of Transportation examined the scene, and then several hours later firefighters were able to extract the driver from the wreck.

Both ramps in the area were closed for about 12 hours for cleanup and repairs.

Anyone with information on the crash who hasn’t yet spoken with police is asked to call Det. Const. Wes Wilson at 905-546-4753.