The big ones (older Sequoias and Redwoods) have thick fire resistant bark and can survive most any fire.
But, I suppose burning up the next generation(s) is not so good...
Sequoias are actually fire dependent for survival. As I recall from school a fire is the only thing that makes them reproduce, or some such thing.
California ecosystem is a fire dependent or tolerant one. We dont get summer rain. This is natural although naturally they were started by lightning and of course not fought.
I dont say this to take away at all from the people here just to point out this is normal like tornadoes or flooding etc. part of the ecosystem. We have to plan and work around it just like Hawaii etc have to plan on volcanoes. It happens.