Mykola Chudak, 66, a firefighter, served for six months, beginning in November 1986, working within 10km (6 miles) of the plant. He focused not on his own role but on the first responders who acted immediately, saying they prevented a far greater catastrophe, often at the cost of their own lives. His service was extended because of a lack of replacements, and years later, he was forced into early retirement due to disability. For him, Chornobyl carries both personal and national significance. "Ukraine must always be grateful to the heroes of Chornobyl," he said. "Being back here, my first feeling is one of immense gratitude for the sacrifice made by my comrades. In many ways, the independence of Ukraine was born on April 26, 1986, in Chornobyl. Without their heroism, an independent Ukraine might not even exist today." [Evgeniy Maloletka/AP Photo]