The death toll in the weekend roof collapse at a Moscow water park could rise by up to 13, Moscow Mayor Yuri Luzhkov said today as rescuers sifted through the wreckage.

Rescue workers with sniffer dogs picked through the ruins of an indoor water park searching for survivors in Moscow today after a roof collapsed on hundreds of bathers yesterday, killing over two dozen people.

At least 21 people were killed and 106 injured when a glass and concrete roof covering a huge, two-year-old Moscow water park gave way in what the mayor called the city’s biggest technical accident.