Workers labored intensely Tuesday to try to restore ventilation to the Siberian coal mine where 43 miners remain missing more than two days after a pair of explosions roared through the tunnels. The death toll from the blasts rose to 47 on Tuesday, the Emergencies Ministry said, and the prospect of pulling anyone out alive appeared to be diminishing rapidly. Ministry spokeswoman Veronika Smolskaya said rescuers searching the tunnels have not established contact with any of the missing. Prime Minister Vladimir Putin traveled to the Raspadskaya mine, about 3,000 kilometers (1,900 miles) east of Moscow, on Tuesday to observe rescue operations, and he raised a series of sharp questions about mine safety and whether the initial rescue work was conducted improperly.