Crowds march through Red Square in Moscow to mourn the death of Russian cosmonauts Georgi Dobrovolski, Vladislav Volkov and Viktor Patsayev, the three cosmonauts killed on Soyuz 11 during descent of their module. The recovery team opened the capsule on 30 June 1971 to find the crew dead. They had been asphyziated after a breathing ventilation valve had been jolted open as the descent module separated from the service module.
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