At least nine people including two children, died and 11 others were injured when the roof of a swimming hall in northern Russia collapsed Sunday, Russian civil defence reported. One-hundred square metres of the roof of building, constructed in 1992, caved in and fell into the pool below with 30 swimmers. More than 300 rescuers with 21 vehicles and four cranes were combing the rubble for victims. The roof was not weighed down with snow, a civil defence person said. Authorities have yet to determine the cause of the accident, which occurred in the Ural city of Chusovoi, 2,000 kilometres north-east of Moscow. Officials have, however, ruled out terrorism. In February 2004, the roof of a swimming and leisure complex in Moscow collapsed, killing 28 people and injuring 110. --SP 2318 Local Time 2018 GMT