In the middle of the night, dozens of homeowners find themselves on a Napa Valley hilltop surrounded by a huge, wind-blown fire. They are suddenly trapped, desperate to escape. Two teams of daring chopper pilots risk their lives in a mission to rescue them, landing in smoke and fire to do the seemingly impossible. Josh Mankiewicz reports Sunday, April 1 at 10:20 p.m. ET/9:20 p.m. CT.