In the 1920s, leaders of the Red Army were searching for an appropriate place to build a science and military complex for inventing, producing, and testing bioweapons.[8] An ideal location for such complex would be a relatively large island 5–10 km (3–6 mi) from a coast. Initial sites discussed for this complex included Lake Baikal, but choices were narrowed down to the Solovetsky Islands in the White Sea, Gorodomlya Island located on Lake Seliger and Vozrozhdeniya Island.[2] The Russian Civil War and several unsuccessful attempts to build the complex from 1936-1941 led to a belief that such a complex must be built far from the Soviet Union's borders with other nations.[2] Vozrozhdeniya Island's location in the middle of the Aral Sea, well within Soviet borders, satisfied this consideration. In 1948, a top-secret Soviet bioweapons laboratory was established on the island which tested a variety of agents, including anthrax, smallpox, plague, brucellosis, and tularemia.[9] In 1954, the site was expanded and named Aralsk-7, one of the main laboratories and testing sites for the Soviet Union's Microbiological Warfare Group tasked with inventing and testing the effects of multiple fatal diseases.[2] In 1971, an accidental release of weaponized smallpox from the island infected ten people, of whom three died. In the 1990s, word of the island's danger was spread by Soviet defectors, including Ken Alibek, the former head of the Soviet Union's bioweapons program.[10] According to released documents, anthrax spores and bubonic plague bacilli were made into weapons and stored at the complex. The main town on the island, where scientists and employees of the complex lived, was called Kantubek, which lies in ruins today, but once held approximately 1,500 inhabitants. The official Soviet name of this city was the same as the weapons complex itself: Aralsk-7.[2] It contained simple infrastructure that consisted of a social club, a stadium, a couple of schools and shops.[2] A unique airfield "Barkhan" was also located close to Kantubek. It was the only airfield in the Soviet Union with four runways, in an intersecting starburst pattern. The weather on the island changed very frequently; thus, planes landed on one of the four runways depending on weather and wind direction at the time.[2] Following the dissolution of the Soviet Union, Aralsk-7 was closed in November 1991.[2] All people who lived on Vozrozhdeniaya Island were evacuated within several weeks; civil and military infrastructure were abandoned and Kantubek became a ghost town.[2] Many of the containers holding biological agents were not properly stored or destroyed, and over the last decade many of these containers have developed leaks. In 2002, through a project organized and funded by the United States with the assistance of Uzbekistan, ten anthrax burial sites were decontaminated.[11]