A woman in her 40s is in hospital after being struck by a wheel that flew off a dump truck in Mississauga.

Peel Regional Police said the woman was walking along Meadowvale Boulevard, near West Credit Avenue, shortly before 8:30 a.m. on Friday.

As she walked on the sidewalk, she was struck by one of two wheels that fell off a passing dump truck, police said.

The woman was rushed to hospital in critical condition.

Police told reporters the truck wheel had separated from the dump truck's axle then struck the woman in the head. Officers said they were looking for a second wheel that also flew off the truck.

Dump truck tire strikes pedestrian

The woman has been identified by co-workers at Mary Kay Cosmetics as Diane Tsialtas.

She was described by colleagues as an “avid runner” who liked to go for walks.

Police and officials with the Ministry of Transportation are investigating.

With a report from CTV Toronto's John Musselman