Lexington firefighters were dispatched to a Lee's Famous Recipe Chicken restaurant Sunday night after a fire was detected outside the building.
The Lexington fire department said someone apparently dropped a lighted cigarette, which ignited mulch next to the restaurant, at 148 Boardwalk, off New Circle Road.
The fire smoldered for some time, firefighters said, creating smoke, which entered and collected in the restaurant's attic. The incident occurred about 8:30 p.m.
The building itself did not catch fire, but firefighters called in inspectors from the Lexington-Fayette County Health Department to make sure that foods in the building were not contaminated.
The case remained under investigation Sunday night.