A South Portland house was heavily damaged by fire Thursday night.

The fire at 53 Lowell St. was reported at 9:20 p.m. When firefighters arrived on scene about 4 minute later, heavy fire was showing in the two-story wood-frame house, according to South Portland Fire Department spokesman Robb Couture.

The home’s single occupant was already out of the house when firefighters arrived. A cat was rescued.

The woman who escaped the blaze was evaluated at the scene but did not need to be taken to a hospital. Courture did not know if she was alerted to the fire by smoke detectors.

The cause of the fire remains under investigation. Couture said it appears the fire started at the front of the house and caused heavy fire damage to both floors.