TEN days after a flash flood inundated a 10km-deep network of caves in Thailand which 12 boys and their football coach had been exploring, the missing team was found alive by rescue divers. But the 13, who were discovered 2km into the cave, are still unable to leave. The way out remains flooded. The monsoon rains are impeding efforts to pump the water out. Some of the boys do not know how to swim. The water trapping them is murky and fast-moving and the tunnels they must pass through are narrow and winding in places. As The Economist went to press, rescue workers were trying to teach the children the rudiments of swimming and diving, to allow them to be guided out.