MAYERTHORPE, Alta. - Residents of a trailer park have been given the all-clear to return home after a fire that RCMP are investigating as a possible arson engulfed a wooden trestle bridge northwest of Edmonton.

The fire started Tuesday afternoon at the Canadian National Railway bridge on the outskirts of Mayerthorpe, forcing students at the nearby Mayerthorpe high school and residents of 38 mobile homes at the Kreek's Krossing trailer park to leave.

Mayerthorpe fire

Thick, black smoke billowed from the burning railway bridge for hours until it collapsed later Tuesday.

Ashley Olsen, spokeswoman for the town of Mayerthorpe, said the fire has been contained and residents were being allowed back.

Kevin Andrea, superintendent of Northern Gateway Public Schools, said students were sent home early over concerns the smoke from creosote in the wood could cause health problems.

Mayerthorpe fire

Water bombers, along with fire crews from Mayerthorpe and surrounding areas, battled the blaze.

A CN spokeswoman said there were no injuries and train traffic was not affected.

Mayerthorpe fire
Residents of a trailer park have been given the all-clear to return home after a fire engulfed a wooden trestle bridge northwest of Edmonton. (Photos from My Mayerthorpe / Facebook)