Some—but by no means all—of the Chernobyl story can now be told. Soviet scientists have assembled enough information from interviews, plant records and computer simulations to describe the chronology of events leading to a severe accident that destroyed a nuclear reactor at Chernobyl on 26 April and spread radiation over much of Europe. A Soviet delegation of 28 specialists headed by V. A. Legasov (Kurchatov Institute) presented a very frank report on the accident's causes and consequences to an experts' meeting sponsored by the International Atomic Energy Agency in Vienna on 25–29 August. Their report places heavy blame on the reactor staff for committing numerous violations of operating rules, one of which left the reactor operating at a power level where the consequences of further violations were greatly exacerbated.