Andover firefighters extinguished a roof fire at the Pfizer facility on Burtt Road on Wednesday, Sept. 16, before flames could spread to the rest of the building.

No injuries were reported, the Andover Fire Department said.

Crews responded to reports of a smoke odor late that afternoon, Patch reported. When they arrived at 1 Burtt Road, they found smoke coming from the roof.

Firefighters ran hose lines inside and outside the building and knocked down the fire quickly. The blaze did not reach other parts of the facility, the department said.

The cause of the fire has not been announced.

Tyler Merullo, an Essex County paramedic who monitors fire calls, described the incident in a post on X that afternoon:

@tmerullo16: "Andover, W/F, 1 Burtt Rd/Pfizer Building, Fire in a rooftop unit"

The post placed the fire in a rooftop unit at the pharmaceutical company's Andover location. The Andover Fire Department has not specified what equipment was involved.

The fire remains under investigation.