Firefighters in the Sierra are using explosives to safely bring down trees. It may sound crazy and a little dangerous, but that’s what firefighting crews are doing as they continue to battle the Fork Fire in El Dorado County. An Eldorado National Forest spokesperson says “fireline explosives” are being used to topple thousands of dead trees that are still standing after the King Fire back in 2014. An Eldorado National Forest spokesperson says “fireline explosives” are being used to topple thousands of dead trees that are still standing after the King Fire back in 2014.