The attack began at about 5pm on Sunday 31 October 2010, when gunmen who had attacked a nearby stock exchange entered the cathedral during the evening Mass and took the congregation hostage. Iraqi and American forces stormed the building some hours later. Fifty-eight people were killed, among them two priests, one shot at the start and one during the siege, and about seventy-eight were wounded. The Islamic State of Iraq, the predecessor of the group that took Mosul four years later, claimed responsibility and followed the attack with a declaration that Iraqi Christians were legitimate targets, which set off a wave of departures from Baghdad. The Syriac Catholic Church has pursued the recognition of the dead as martyrs and marks the anniversary each year.