A Sunday morning house fire in South Oakland was caused by flammable construction materials, Pittsburgh fire officials said.

The Pittsburgh Bureau of Fire was dispatched to the 3200 block of Dawson Street near Frazier Street just before 8:30 a.m, the City of Pittsburgh reported. The second alarm was called just before 9 a.m.

The homeowner told firefighters he had been doing construction work — which included working with chemicals like paint thinner — in the rear of the home prior to the fire.

Fire Investigation Unit detectives entered the residence and were able to confirm the fire originated from the “spontaneous combustion of those construction materials,” the city said.

Thick, dark smoke billowed from the house’s second floor, according to TribLive news partner WTAE, and firefighters had to use a ladder to try to get the flames under control throughout Sunday morning.

All residents were able to safely evacuate the house, and no injuries were reported. The fire was contained within the single residence.