St. Louis (ksdk) - People sleeping in an office were rescued during a fire Christmas morning.

The St. Louis fire department found the three inside the building on Cote Brilliante.

The owner was allowing them to sleep there in exchange for keeping an eye on the warehouse. But, there were no working smoke detectors inside the building.

"I don't even want to think about what could have happened" said Fire Captain Garon Mosby. "We've been pushing this really hard. Smoke alarms save lives. It's something that the fire department does free of charge we will come out and install."

Firefighters say a space heater sparked the fire.