SALT LAKE CITY — Three apartment units were damaged by a fire early Tuesday morning that officials believe was cause by a discarded cigarette.

The fire started around 12:30 a.m. Tuesday at 163 S. 600 East, according to Salt Lake City Fire Department spokesman Jasen Asay. Crews responded quickly and gained control of the fire, Asay said, but were initially impeded by a live disconnected power line near the back of the three-story building.

Two of the apartment units received heavy smoke, fire and water damage, Asay said. The third unit received only smoke damage.

Investigators determined the fire to be accidental, but one of the building's occupants told firefighters that she had discarded a cigarette into a garbage can on the back patio. A second-story deck above the patio collapsed during the fire, which spread from the patio into the building.

Five adults living in the apartment units were displaced during the fire, but no injuries were reported.

Asay said that investigators had not yet determined a cost of damage due to the fire.