An apartment fire in southwest Atlanta that displaced at least eight families Thursday morning has been ruled arson by investigators, according to Atlanta Fire Rescue.

No one has been taken into custody, but officials have identified a person of interest, AFR spokeswoman Alyssa Richardson confirmed. That person’s identity has not been released.

Crews were sent to the Adams House Apartments in the 2280 block of Campbellton Road at around 9 a.m. and immediately noticed heavy smoke in the back of the building, fire Capt. Taurus Durrah said. The blaze originated in a bottom-floor unit and extended into the attic space, he said.

Durrah estimated that three or four units were damaged, with eight families being displaced from their units.

All of the residents self-evacuated, authorities said. Once crews determined the building was empty, they were able to begin the process of putting out the fire.

Like other fully involved fire incidents this summer, departments have to take the oppressive heat into consideration. By 10 a.m. Thursday, actual temperatures were in the 80s, but felt like the mid-90s.

“What we did was try to go ahead to work with what we have,” Durrah said. “We are sending more units so that way we can rotate crews out a lot sooner, so that way we don’t have anyone get overwhelmed with heat exhaustion or anything like that.”

Durrah said crews are encouraged to start hydrating before their shift in order to prepare themselves for the heat.