Santa cruz firefighters responded to a structure fire yesterday at 6:39 p.m. the flames were reported by a first alarm security guard on the 2-hundred block of washburn avenue. the fire was burning on the 2nd-story balcony of a residence. Firefighters were able to extinguish the blaze in about 10-minutes. Nobody was at home at the time, and no injuries were reported. Discarded cigarettes (that were tossed in a potted plant) are believed to have been the cause. About 10-thousand dollars worth of damage was incurred. Firefighters from U-C-S-C fire also responded to the incident, as did santa cruz police officers.