So far, many clues to the origins of the deadly Eaton fire, which started in the area just after 6 p.m. that evening and went on to kill 17 people, have pointed to the brushy hillside where a tangle of electrical lines stretch up Eaton Canyon.

Weeks after wildfires that killed at least 29 people and destroyed entire neighborhoods, Southern California is facing another extreme-weather threat: Too much rain.