In the case of the Eaton Fire, the investigators are likely to use magnets to help them hunt for the tiny, melted pieces of metal that could have been shed by power lines if they slapped together. But the existence of the metal doesn’t necessarily indicate that’s how the fire started, Nordskog said.

Gloria Lynn Mandich, 60, was detained over an alleged connection with a brush fire near Leo Carrillo State Park in Los Angeles County.