Fire struck an optical components factory at 1916 Greenleaf St. in Evanston this afternoon.
The fire was first reported about 2:15 p.m. and Evanston fire crews had managed to bring it under control in less than half an hour.
All the workers in the building managed to get out safely on their own.
The fire apparently broke out in an area close to the roof, above the location of the building's sprinkler heads.
The 16.000 square foot building houses Sterling Precision Optics which makes optical components and precision machined glass.
Fire crews from other communities including Skokie and Morton Grove were called in as backup for the Evanston crews.
Update 9:10 p.m.: Fire Division Chief Paul Polep says first companies arriving at the scene encountered heavy smoke and moderate fire conditions on the second floor of the building.
Upon making entry into the building fire companies observed an activated sprinkler system keeping the fire in check until crews were able to quickly extinguish the fire.
The business suffered significant smoke and water damage.
There were no firefighter injuries. The cause of the fire still remains under investigation.