Images show a blaze, emergency services and law enforcement after gunmen opened fire at a Moscow concert hall killing at least 40 people and wounding 100, according to authorities. The motives and the identity of the attackers remained unknown, though the Islamic State group made a claim of responsibility. "I don’t know what to do, complete hopelessness," says Semyon Khraptsov, whose wife attended the concert and is now missing. "I tried calling five hospitals, all the lines were busy," he says. IMAGES AND SOUNDBITES