A faulty extension cord started a fire that destroyed two school buses and damaged two others on Monday, according to Edmonton Fire Rescue Service. 

"The fire originated at the bumper of one of the school buses and the cause was an arc in the extension cord that was plugged into the block heater," a statement from EFRS said. 

A shed was also charred by flames.

The cost of the damages is estimated at $115,000.

Firefighters responded to the area of 51 Avenue and 66 Street just after 6 p.m.

“When they were driving, they saw flames coming up from the area, and when they arrived they found two buses fully engulfed,” District Chief Todd Weiss said of his crew. 

Firefighters had the flames out before 7 p.m.

There was no name on the business where the fire happened but it appeared at least 20 buses and several semis were stored in the fenced compound. 

Weiss confirmed firefighters called police to the scene, but he wouldn’t say what prompted the call. 

A patrol officer was on site Monday working with fire investigators to pinpoint a cause and damage estimate. 

A spokesperson for EPS Southeast Division said on Monday that the fire was not suspicious.