RUSSIA flattened part of an apartment building while residents slept on Friday in missile attacks near Ukraine's port of Odesa that authorities say killed at least 21 people, hours after Russian troops abandoned the Black Sea outpost of Snake Island. Locals in the resort village of Serhiivka helped workers pick through the rubble of the nine-storey apartment block, a section of which had been completely destroyed in the early-morning strike. Walls and windows of a neighbouring 14-storey apartment block were also damaged by the blast wave. Nearby holiday camps were also hit. "We came here to the site, assessed the…