Al Roker talks to climate scientist Alexander Gershunov about the conditions that made the L.A. wildfires so devastating.

Photograph by Mark Thiessen, National Geographic Before and after a home burned down in the Smiley Park neighborhood of Running Springs, California during the 2007 Slide Fire. Because of the ...

Strong Santa Ana winds fueled wildfires that burned across Southern California for more than three weeks, forcing tens of thousands of residents out from their homes.