The U.S. Forest Service has been sending out crews to fight wildfires without masks for decades. Hannah Dreier, a New York Times investigative reporter, reveals the sometimes deadly repercussions of that policy. Video by Hannah Dreier, Christina Thornell, Gabriel Blanco, Coleman Lowndes, Stephanie Swart, June Kim, Nikolay Nikolov and Lauren McCarthy#hotshots#wildlandfirefighter#wildfires#firefighters