Dr Zaher Sahloul is one of three physicians from Chicago, USA who have travelled to the Syrian war-torn city of Aleppo to offer support to the doctors there. He says he has been staying “at a hospital that was bombed several times and the people in Aleppo built it underground for protection”. His story offers a rare insight into life in a city that has been destroyed by fighting between rebels, so-called Islamic state and the Syrian government.