A fire in a one-story commercial building in downtown Los Angeles was stunted by the building’s sprinkler system and extinguished in 40 minutes Thursday morning, authorities said.

Firefighters responded to the building located at 737 Crocker St., south of Seventh Street, at 3:32 a.m., according to Nicholas Prange of the Los Angeles Fire Department.

“The growth of the fire was initially stunted by a fire sprinkler activation inside the building, minimizing the spread and damage,” Prange said.

A knockdown was declared at 4:12 a.m.

No injuries were reported and the cause of the fire was under investigation.