An elderly man is in critical condition after a fire broke out at a Fullerton home containing him, a woman and several dogs.

The fire broke out at about 11:45 p.m. Tuesday night near Glenhaven and Highland avenues, and when firefighters arrived, they found flames coming from the attic and burning through the roof of the single-story home.

While the cause of the fire remains under investigation, officials believe the blaze began in the garage, possibly as a result of pack-rat conditions.

“We did have some challenging conditions inside the structure,” said Battalion Chief Jon Fugitt of the Fullerton Fire Department. “I like to remind people to make sure they keep their houses in nice, orderly fashion so we can complete our tasks.”

Firefighters credited smoke detectors for alerting the occupants before anyone was killed by the blaze, which took half an hour to extinguish.

The man was rescued by firefighters and has been taken to UCI Medical Center in Orange to be treated for multiple burn injuries, while the woman escaped on her own.

Several dogs were in the home, and three of them were transported for medical care, though they’re all expected to be OK.