Death toll in Russian mine tragedy rises to more than 50 - CNN
Authorities said 239 had made it to the surface.
President Vladimir Putin said he had spoken with the governor and emergency officials, and the Kremlin said he had ordered the emergencies minister to fly to the region to help.Kemerovo declared three days of mourning.In 2007, the region was the site of the worst mining accident since the collapse of the Soviet Union when an explosion at the Ulyanovskaya mine claimed the lives of more than 100 people.In 2010, explosions at the region's Raspadskaya mine killed more than 90 people.