The fire was reported at 2:22 a.m. in the 100 block of Harkness Avenue, according to the Pasadena Fire Department.
Crews encountered heavy smoke and fire that threatened to spread to the single-story main home on the property, which was evacuated by its residents, according to a report from the scene.
Four engines, two rescue ambulances and two battalion chiefs responded to the scene along with about 30 firefighters, according to department spokeswoman Lisa Derderian.
“The fire was located within a converted garage to the rear of the property with minor (spread) to a shed and the main house,” Derderian said. “During a secondary search, a deceased dog was found within the converted garage.”
Crews arrived within 10 minutes of the call and had the flames doused within 15 minutes, she said.