Prosecutors with the Los Angeles County district attorney's office said the unidentified youth's case will be turned over to the state Department of Children and Family Services for evaluation of the boy's home situation at a horse ranch northeast of Santa Clarita, the Los Angeles Times reported Wednesday.
"The evidence presented by sheriff's investigators was that the fire was caused by the 10-year-old boy playing with matches and accidentally igniting the brush. There is no evidence of (arson) intent on the part of the minor," said Sandi Gibbons, a district attorney's spokeswoman.
The Oct. 21 fire forced the evacuation of 15,000 people, and while the youth won't be charged, his parents could be found civilly liable for millions of dollars in damages, the newspaper said.
California fire officials said generally when someone under 12 sets a fire, the actions are considered "playing with fire" and not arson.