"Climate change, including increased heat, extended drought, and a thirsty atmosphere, has been a key driver in increasing the risk and extent of wildfires in the western United States," the National Oceanic and Atmospheric Administration says.

Fire investigators are working to determine whether the Los Angeles blazes were the result of an intentional act, an accident or damaged utility lines.

In Los Angeles’s chaparral-covered ecosystem, wildfires in the mountains are an annual ritual. But when those fires leaped into residential neighborhoods earlier this week, killing 11 people and destroying thousands of homes,