ATLANTA — Fire investigators are working to determine what caused a house fire in southwest Atlanta that killed a woman and a boy Wednesday night.

Atlanta Fire Rescue crews responded to the 2400 block of Waters Street near Cleveland Avenue shortly before 9 p.m. Fire officials say firefighters arrived within five minutes of the 911 call and found heavy flames coming from the home.

A man and another boy managed to escape the house and attempted to put out the fire with water before calling 911.

When firefighters arrived, they were told a woman and another boy were still trapped inside. Crews located both victims, but neither survived.

The man was treated for smoke inhalation, while the boy who escaped suffered minor injuries.

The man reportedly told firefighters the fire started near a couch, but officials have not confirmed the cause.

Investigators remained at the scene overnight to determine how the fire started.

Fire officials are reminding residents to leave their homes immediately and call 911 if a fire breaks out rather than attempting to extinguish the flames themselves.

Officials also recommend replacing batteries in smoke and carbon monoxide detectors when clocks change.

It remains unclear whether the home had working warning devices.

Officials haven’t released the names of the victims.

WSB Radio’s Ashley Simmons & Graham Carroll contributed to this story.