Yemeni men look through a hole in a building damaged by a recent Saudi-led airstrike which, hit a site that many believe was a large weapons cache in Yemen's capital, Sanaa, Saturday, April 25, 2015. With combatants fighting in neighborhoods and Saudi-led coalition warplanes pounding Iran-backed rebels from the sky, Yemen's war is wreaking a particularly bloody toll among civilians: more than 550 have been killed in the past month, including 115 children, the U.N. said Friday. AP