Sprinklers helped prevent a vehicle fire inside a Hopkinton vehicle painting business from spreading through the building, which had fire trucks parked inside, officials said.

Firefighters were called at 1:30 a.m. to the building at 17 Winter Street.

“Upon their arrival, they entered the building and found heavy smoke conditions in the building. Upon further investigation, they found a motor vehicle fire in the paint booth at this location,” Hopkinton Fire Department Chief William Miller said. “A sprinkler had activated and held the fire in check.”

There were no employees in the building at the time, and no injuries were reported.

The cause of the fire remains under investigation.