Arson investigators are trying to figure out what sparked a house fire that flared up twice in southwest Houston.

Officials with the Houston Fire Department said firefighters were called out to the home on Fawn Terrace two times within five hours.

Late Sunday night, the homeowner’s son noticed smoke coming from an air-conditioning unit. He heard screaming from outside and got all seven people outside safely.

Hours later, the family returned to find the house on fire again. The second time, flames damaged a neighboring house.

Firefighters said it took over an hour and a half to knock the fire out.

Fire crews said no one inside was injured, although a firefighter was taken to the hospital with non-life threatening injuries.