By Steve Rosenberg BBC, Moscow In a lawyer's office in Moscow, Vyacheslav Zdanovsky sits with a pile of papers and documents. He's preparing for the legal battle of his life. Vyacheslav is suing the Moscow government for half a million dollars: compensation, he believes he is owed as a result of the Moscow theatre siege. He is one of 49 former hostages and relatives of the dead who are taking the authorities to court for moral and physical damages. Sitting around a table in the lawyer's office, Vyacheslav shows me photographs of his wife Elena - and tells me the story of what happened to her last October. "We'd gone to the theatre to see the musical 'Nord Ost' with our two sons. Suddenly armed Chechens ran in and took everybody in the theatre hostage." When Russian special forces launched their assault, Vyacheslav and his children got out alive. Three days later Elena's body was discovered in a local mortuary. "I want to sue the Moscow authorities for failing to prevent such a terrible terrorist attack in the centre of our capital," Vyacheslav told me. "How could they fail to stop dozens of armed rebels from driving through the city? Why didn't the state protect us?" More than 120 hostages were killed in the rescue effort. Hundreds more survived, but were rushed to hospital, knocked unconscious by a gas used to put the Chechens to sleep. The Moscow government says it is unfair to hold it responsible for the tragedy. Or to accuse it of not supporting victims. The city authorities have paid out more than $3,000 to each family which lost loved ones. The lawyer leading the campaign for compensation, Igor Trunov, says that is no defence. Long battle "By law it's up to the courts to set the level of compensation. Not local officials," explained Mr Trounov. "The law also says that it's the local authorities - not the Russian Government - which can be sued for compensation after a terrorist attack." Mr Trounov is prepared for a long fight in the courts. He fears the compensation case could drag on for years. But it is a battle he - and clients like Vyacheslav - are determined to win. "We want the whole population to look at us, to realise that this could happen to anyone here: no-one is protected. Today it was us, tomorrow it could be you. Now everyone must work together to change things," said Vyacheslav.