The fire at the home in the 1800 block of Rock Springs Road was reported about 10 a.m. Monday, said San Diego sheriff's Lt. Dave Schaller.
First on the scene were deputies from the sheriff's San Marcos station, Schaller said. The house was filled with flames and smoke and the deputies tried but failed to enter to look for people inside.
When San Marcos firefighters arrived, they put the fire out in about 25 minutes, according to fire officials. The home, which was filled with clutter and trash, sustained heavy fire and smoke damage, and firefighters found the body of a small dog inside the structure, they said.
Deputies then learned the home was supposed to have been auctioned off on the day of the fire and the homeowner, 62-year-old Duncan Kendall, was nowhere to be found, Schaller said. Although there were no obvious signs the fire was deliberately set, arson investigators were called to the scene to assist in the investigation.
Kendall's son was located and told deputies he had just learned his father had lost the house, Schaller said. The son had no idea where his father was and requested a missing persons report. Due to the circumstances of the foreclosure and subsequent fire, Kendall was listed as "missing - at risk,'' Schaller added.
Kendall's car, which is owned by his son, was also missing. It's a 2008 four-door Ford Focus, California License number 6EJX949, according to Schaller.
Detectives requested that anyone with knowledge of Kendall's whereabouts or the whereabouts of the car he was apparently using call the San Diego Sheriff's Department at 858-565-5555. Tipsters can also call Crime Stoppers at 888-580-8477. All tips can be submitted anonymously.