in 25 years. >> it's been quite the firefight. we've had winds moving up slope, down slope, across the slope. we've had firefighters being pushed out and run out, and then turning around and coming back and getting right back on those structures. >> reporter: while it's still unclear what sparked the cave fire, first responders say california's changing climate, marked by more-severe droughts and extreme temperatures, is fueling these fires. and looking at this landscape, it's hard to believe homes have not been destroyed. heavy rain is expected tonight, but it comes with a new threat-- mudslides. all this vegetation is all but destroyed, making it nearly impossible to hold back this mountain. norah. >> o'donnell: all right, jonathon, thank you. tonight, congress is making president trump an offer he might just refuse as it announced the date for the next impeachment hearing. paula reid is at the white house with the new details. >> reporter: calling it a new phase in the impeachment inquiry, a top house democrat is