The Estonian president on Friday extended condolences to its neighboring country Latvia after a supermarket collapse tragedy left over 40 dead in its capital Riga. "I am in mourning with the Latvian people and bow my head in memory of the victims," Estonian President Toomas Hendrik Ilves said in a letter to Latvian President Andris Berzins. "Our thoughts are with the Latvian people in this sad time," he was quoted as saying in a report by Estonian Public Broadcasting ERR on Friday. Among those killed were three rescue workers who entered the building before a collapse of a second section, the report said. The death toll rose sharply after the discovery of a second retail area buried under rubble.