Hawaii island firefighters extinguished a fire at unpermitted structures in Orchidland Estates that a resident may have accidentally started when she used a propane torch to kill ants.

Eleven units with 17 firefighters responded to the fire near 16-1590 37th Avenue at about 6:30 p.m. Thursday. When they arrived, they observed heavy black smoke and heard multiple small explosions, according to the Hawaii County Fire Department.

A resident told firefighters she was using a propane torch to kill ants and may have accidentally set pallets on fire, according to a fire department news release.

A large amount of scrap metal on the property hampered firefighters’ efforts to access the unpermitted structures. They brought the fire under control at 9 p.m. Some firefighters remained on the scene to monitor the fire and extinguish hot spots.

The fire department said the small, multiple makeshift structures were destroyed by the blaze.

Abandoned vehicles, appliances and roofing material were also observed on the property.