The crusaders reached Jerusalem on 7 June in the punishing midsummer heat with only 15,000 men remaining. Initial attacks, without siege towers to breach the walls, were unsuccessful. Luckily, European ships had just arrived at Jaffa, two of which were beached and broken up for timber, and the leader of the First Crusade, Tancred, stumbled across a cave containing 400 pieces of timber from which two large siege towers were constructed. The final attack began on the night of 14 July. Raymond of St Gilles’s siege tower was destroyed but Godfrey of Bouillon moved the second siege tower to a weak point in the wall and gained entry into the city, drawing defenders from the south. The crusaders then engaged in widespread massacre, burning the Jews inside their synagogue and slaughtering the Muslims on the Temple Mount. A small group, including the city governor, was allowed to escape after blockading themselves in the Tower of David.