Chechen militants had held hundreds of hostages inside a Moscow theatre for three days, the audience and performers alike trapped with explosives wired around the building. Negotiations dragged on with no resolution in sight, and the gunmen threatened to start killing captives if Russian forces did not withdraw from Chechnya.
Before dawn on this day in 2002, Spetsnaz special forces pumped an unidentified narcotic gas through the ventilation system and stormed the building. The assault killed the militants, but the gas proved just as deadly to the people it was meant to save: roughly 130 hostages died, most from the effects of the chemical agent rather than gunfire, and Russian authorities refused for years to disclose exactly what it was.
