A fire that completely destroyed a John Deere tractor dealership and repair shop in Sherbrooke earlier this week has been ruled accidental.

The fire overnight Wednesday caused some $3 million in damage to the JLD-Laguë Company building located on Queen Street in the Lennoxville area.

Flames were bursting out of the building when firefighters arrived at the scene after getting a call around 1:30 a.m.

"The commercial building was stocked with combustible materials, tractors, tires and equipment," said Daniel Gringas, the fire department's deputy director of operations.

"Quickly, we had to retreat because the structure is made of steel and it became unstable. It was dangerous for our team."

Gingras said the fire was likely caused by electrical or mechanical issues, which were aggravated by the combustible materials in the building.

By 5 a.m. Thursday, the fire was under control, but firefighters were still busy controlling various hot spots in the building.

JLD-Laguë's services manager Patrick Roy said he heard from a colleague that the alarms were going off at the dealership, and firefighters were already on scene when he arrived shortly afterwards.

He said he'd hoped to get some of the machinery out of the way, but it wasn't possible.

"A huge blaze was coming out of the windows and through the roof," Roy said. "When we were able to open the back door there was a lot of smoke."

The equipment destroyed by the fire will be replaced wherever possible to fill outstanding orders and make sure customers can do their work, Roy said.

He said he's positive they will rebuild after the insurance valuators do their work.

The building is a total loss, Gringas said. A total of 25 firefighters worked to extinguish the fire.