With air raid sirens and the thump of explosions now a familiar night time sound to residents of Kyiv, increasing numbers have taken to sheltering in the city’s deep underground metro stations, battling boredom as they wait for what comes next. Although Kyiv has so far been spared the intense bombardment seen in cities like Kharkiv or Mariupol, authorities say at least 60 civilians have been killed in the capital since Russia launched its invasion of Ukraine on February 24. Pre-dawn explosions, audible across the city have become a routine part of life, with the debris from missile strikes wre…