THREE RIVERS, Calif. (AP) — Firefighting crews are using a novel technique to defend California's iconic giant sequoias from a lightning-caused wildfire in the Sierra Nevada.

Firefighters have wrapped the base of the world’s largest tree in fire-resistant aluminum and other trees and buildings in Sequoia National Park are also wrapped. That's to protect the General Sherman Tree and the others from a wildfire that's expected to reach a grove of 2,000 sequoias within days.

Fire officials say the fire didn't grow much on Thursday. But a wildfire in the region last year killed thousands of sequoias, some of them as tall as high-rises and thousands of years old.