By Fazelminallah Qazizai , Omkar Khandekar A crowd gathers outside Kabul's Omid Addiction Treatment Hospital, where the United Nations says an airstrike killed more than 100 people on Monday. Fazelminallah Qazizai for NPR hide caption KABUL, Afghanistan — On Monday night, residents living near the Omid Addiction Treatment Hospital in the Afghan capital heard a sharp sound tearing through the sky, followed by an explosion. Two days later, Abdul Basir Watan joined dozens of inmates' families crowding outside the hospital in central Kabul. They listened to doctors donning white medical gowns read out the names of survivors over a megaphone. A faint smell of burnt wood and plastic hung in the air. Through the bars of the iron gates, they saw a mound of concrete and metal where a building once stood. Watan said his cousin Zamarek was seeking drug addiction treatment at this facility for the past four months. "He is not on the list of wounded. He is not on the list of dead," said Watan.…