L.A. had a significant temperature drop, with an average of 50 degrees—8.6 degrees lower than the historical five-year average.

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.

Much-needed rain has begun to fall over Southern California, bringing relief to the drought-stricken region but also the threat of toxic runoff.