CAL FIRE SLO responded to reports of a structure fire Monday night.
The fire broke out at Camp San Luis Obispo near O'Connor Way and Sutter Avenue at around 10:05 p.m.
Fire officials say when they arrived they found a 40X40 building fully engulfed in flames.
Firefighters were able to get the fire under control due to a quick response.
Firefighters will remain on scene for two to three hours mopping up any hot spots.
The cause of the fire is under investigation.