LOS ANGELES (AP) — A storm of historic proportions dumped a record amount of rain over parts of Los Angeles on Monday, sending mud and boulders down hillsides dotted with multimillion-dollar homes while people living in homeless encampments in many parts of the city scrambled for safety.

About 710,000 people statewide were without power Monday evening.

The storm was the second one fueled by an atmospheric river to hit the state over the span of days.

Virtually all of Southern California was under flash flood advisories and watches, including the Los Angeles area, where between 5 and 10 inches (12.7 to 25.4 centimeters) of rain had fallen and more was expected, according to the National Weather Service. At the downtown measuring station, 6.7 inches of rain had fallen by Monday afternoon, nearly half the yearly average of 14.25 inches. It was already the third-wettest two-day period since 1877, the service said.