The body of Karen Hunter was discovered inside her home in the El Capitan Mobile Home Park at 1425 E. Madison Ave. Sunday evening, according to the San Diego County Medical Examiner's Office.
The fire was reported at 6:53 p.m., El Cajon city spokeswoman Monica Zech said.
About 20 firefighters knocked down the flames in less than 15 minutes, saving nearby trailer homes. Once the fire was out, they discovered Hunter's body, she said.
The fire caused $75,000 damage to the trailer and its contents. The cause of the blaze was under investigation.
Hunter's age was not immediately determined, according to the Medical Examiner's Office.