Homicide investigation underway after 2 people, dog found dead inside Diamond Bar home after fire

DIAMOND BAR, Calif. (KABC) --

Two people and their dog were found dead inside a home after a fire in Diamond Bar, and authorities said the incident is now a homicide investigation.

Authorities said they are looking for the couple's son, who they believe has mental health problems. They want to find him and speak with him about what may have happened at the home.

Firefighters received a call about the house fire around 4:44 a.m. Friday in the 3600 block of Crooked Creek Drive. It took crews a little more than 30 minutes to knock down the blaze.

When firefighters searched the home, two people and the dog were found. Sheriff's officials then arrived and determined it was a homicide.

"It appears to be a husband and wife - we're assuming because it's in the bedroom that belongs to a husband and wife, but we can't confirm that yet until we get a coroner out here to get a better look. The bodies are so badly damaged. There's a dog in the bedroom as well found burned and dead. We don't know if these people were killed before the fire, or how the fire started just yet," Lt. John Corina said.

Authorities said the victims were an elderly couple who lived with their adult son. He wasn't in the home at the time of the fatal fire.

The cause of the fire is under investigation, but authorities said some type of accelerant - possibly gasoline - may have started the blaze.