Gainesville firefighters responded Tuesday afternoon to a fire at Retreat at McEver Apartments at 1200 Eagle Eye Road.Light smoke was coming from an apartment on the second floor, and the fire was extinguished quickly, Gainesville Fire Chief Jon Canada said. The apartment’s sprinkler system had extinguished most of the fire and it was contained to one apartment unit, Canada added.Firefighters removed smoke and water from the apartment.Investigators concluded the fire was accidental and started from a flare gun that was accidentally discharged inside the apartment, Canada said.No one was injured in the 2 p.m. incident. Damage is estimated at $5,000.