Officials cautioned that ash in recent burn zones was a toxic mix of incinerated cars, electronics, batteries, building materials, paints, furniture and other household items.

Less than an inch of rain fell in most areas, but it was enough to loosen Los Angeles hillsides burned bare by the recent blaze near the Pacific Palisades.

Rain began falling in parched Southern California on Saturday in a boon for firefighters who were mopping up multiple wildfires. But heavy downpours on charred hillsides could bring the threat of new troubles like toxic ash runoff.