Firefighters guard California sequoias as wildfire threatens ancient trees

California’s beloved giant sequoia trees — the largest trees in the world that can live for thousands of years — are being threatened by the 54,900-acre Garnet Fire that entered the McKinley Grove in the Sierra National Forest on Monday. And firefighters are going to great lengths to protect the towering trees — from running a 24-hour sprinkler to deploying parachuting firefighters that have been specially trained to scale the trees to extinguish treetop fires sparked by drifting embers.