MONMOUTH — Investigators have determined the fire that destroyed a garage and workshop at a commercial apple orchard late Saturday began in the south end of the building.

Due to the extensive damage, however, the exact cause of the blaze is undetermined, officials said Monday.

“There is nothing suspicious at this time,” Chief Dan Roy of the Monmouth Fire Department said.

Roy and at least one representative of the Office of State Fire Marshal spent hours at the Cooper Farms Holdings facility at 155 Norris Hill Road on Monday, a day and a half after passersby reported seeing a fire at the facility.

The fire drew a massive response, drawing fire crews and equipment from surrounding towns and Augusta and Lewiston, along with three ladder trucks. An estimated 75 firefighters worked to put out the fire before it could take hold in a larger, adjacent building.

While the fire was knocked down quickly, it caused hundreds of thousands of dollars worth of damage to a garage and workshop space that housed vehicles, farm equipment and fuels and other combustible materials.

For property tax purposes, the town of Monmouth values the property, part of Cooper Farms Holdings, at nearly $1.5 million. Roy estimated the loss at close to $1 million for the building, its contents and damage to the processing facility, which is insured.

On Sunday, Roy said security video from the scene showed the fire had been burning for two hours or more before it was reported. The property is at the end of a long driveway and screened by trees.