The Columbia Fire Department responded to what was called in as a possible barn fire at 1637 Mule Road north of Columbia in rural St. Clair County shortly before 7:30 a.m. Thursday.

Upon arrival, it was determined to be a 15-by-20-foot chicken coop that had already burned to the ground. A dozen chickens died in the blaze, a fire official said.

After reviewing surveillance video footage from overnight, the homeowners were able to determine that the fire had started about 1 a.m., unbeknownst to them.