A four-year-old Kitchener girl is in hospital after an incident with a snowmobile Sunday.

The four-year-old and her mother, a 29-year-old from Kitchener, were riding a snowmobile in the parking lot of Poll Transport, a business in Wilmot Township.

Police say the snowmobile suddenly accelerated and drove under the cab of a parked tractor-trailer. The mother and daughter were both knocked off the snowmobile, which continued on under the cab and off an embankment before stopping in a nearby cornfield.

Both the mother and the daughter were taken to hospital.

"The mother was released after being treated at hospital. [The daughter] was transported to Hamilton by air ambulance with serious injuries," said Sgt. Dave Reibel of the Waterloo Regional Police Service.

A snowmobile trail runs behind the parking lot, and residents say many snowmobilers park in the lot before hitting the trail.

Police continue to investigate the crash, but one thing they’re already sure of is that neither victim was wearing a helmet at the time of the collision.

“The fact that neither party was wearing helmets is the biggest one we’re looking into,” said Reibel.

While the Snowmobile Act says helmets must be worn at all times while snowmobiling, there are exceptions for situations such as snowmobiling on your own property.

There are a few homes on the site of the parking lot, but neighbours say none of them are inhabited by a 29-year-old woman.

Graham Snyder is a district governor with the Ontario Federation of Snowmobile Clubs. He says whether it was their own property or not, both mother and daughter should have been wearing helmets.

“Anything could happen at any time,” he said.