Ten years ago, on October 23, 2002, Chechen militants seized the Dubrovka theater in Moscow, taking some 900 people hostage. On October 26, Russian security forces launched a full-scale assault in which all the armed radicals and 130 hostages died. Most of the victims were killed by a narcotic gas pumped into the theater to subdue the hostage-takers. These photos show how the crisis unfolded over four agonizing days.