Millions of Southern Californians were on edge as winds began picking up during a final round of dangerous fire weather forecast for the region where two massive blazes have killed at least 25 and destroyed thousands of homes.

Firefighters battling two fires that have wreaked destruction across Los Angeles for nine days could get some respite on Thursday from the weather. The hurricane-strength winds that initially fanned the flames and hampered rescue efforts have weakened into much lighter gusts.

Firefighters held the line against two massive wildfires that have ravaged parts of Los Angeles for the past week, even as desert winds and a parched landscape presented extremely hazardous conditions.

A warmer, drier climate means wildfires are getting worse, and encroaching on cities — with devastating impact. Toxic chemicals from those burns can get into damaged drinking water systems, and even filtering or boiling won’t help, experts say.