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

A new fast-moving wildfire has erupted in Los Angeles County, triggering evacuations in a region already reeling from the most destructive fires in its history. The Hughes fire ignited north of the city on Wednesday afternoon,