. >> the cassel fire was a wake-up call.7,500 to 10,600 trees were destroyed in that one fire alone. >> reporter: started by lightning in august 2020, the cassel fire was part of the sequoia complex that burned more than 174,000 acres, scorching several sequoia groves. >> it was devastating, heartbreaking. everything had been incinerated. it was a field of the world's largest burned-up toothpicks. >> reporter: after decades of suppressing forest fire, other trees and brush have grown rampantly around the sequoias. >> the fires that used to burn every five to ten years in the sierra would just keep down the competition and reduce the fuel naturally. >> reporter: on land owned by the save the redwoods league, we hiked out to see just how deadly the cassel fire was here. >> for us to see 10% to 14% of the total of giant sequoias alive killed in one year, in one fire, there's nothing to compare that to. >> reporter: yet fire in and of itself is not the enemy of the giant sequoia. >> their cones open up. their seeds start to germ

i want you to hear from mike ca cassel. they took their 3-year-old girl into the basement and that is what they're sure saved their lives. take a listen. >> it look as little more like oklahoma today, but it's south jersey, farm town. never would have thought. >> reporter: people keep saying three minutes. how desperate do you think it would have been had you not heeded the warning? >> i think it would have been dire for a lot of people. i mean, you see ore there the house is completely flattened unfortunately. they did the same thing. they went in the basement. something felt different, and ev did the right thing fortunately. >> reporter: it certainly was different. the governor of new jersey says there are at least 23 deaths, but none in this neighborhood. people's dream homes, kate, have turned into complete rubble. and the next question is do you rebuild? i mean you heard mike cassel say, this is new jersey, not oklahoma, and they don't know what the insurance will cover. and, quite frankly, kate, they're not sure they