CHERNOBYL, UKRAINE: Workers enter the so-called diarator stack, where they drill holes in the concrete to install support beams that are supposed to stabilize the outward leaning Western wall of Chernobyl's nuclear reactor, which is in danger of collapsing. Their dark workspace is located close to the center of the explosion and is so highly contaminated that they can only work in 15-minute shifts despite wearing highly protective gear and respirators.