Bomb and arson investigators were on scene looking into the cause of a fire that broke out inside the home on Lakeside Avenue.
However, hours later, the fire was ruled accidental and unintentional officials said.
When fire crews got to the scene just after 9 a.m. Tuesday, they said they were surprised to see the size of the fire and how much of the home was involved.
Flames were seen coming out of the windows on the front of the house, said Lakeside Division Chief Jim Kirkpatrick.
“It’s not typical during the day to have the whole building involved,” he said.
There were no injuries.
Three people living in the home were already outside when firefighters arrived.
The occupants have been talking with San Diego County sheriff’s deputies with the Bomb Arson Unit according to Kirkpatrick.
Close to three dozen firefighters fought the fire. As of 10:30 a.m., crews were still putting out hot spots in and around the home.
CHP officers shut down Lakeside Avenue at Palm Row and Vista Camino during the incident.