No injuries were reported on Thursday when WorkForce Oklahoma filled with smoke.
The Stillwater Fire Department responded to 3006 E. 6th Ave regarding a structure filling with smoke.
SFD Battalion Chief Dusty Stokes said the first unit on scene found light smoke in the attic of the building.
Firefighters checked air handling on the roof and the back of the structure.
Stokes believed the fire started from an air handling unit.
SFD was assisted by Oklahoma Highway Patrol and Stillwater Fire Department.