The major victories of the First Crusade were won by employing the basic tactics of siege warfare. At At the vital city of Antioch, the crusaders nearly lost their army to starvation and disease as they attempted to wait out the occupants behind the massive city walls. They were finally able to break the city's defenses through the duplicity of a member of the garrison who secretly let in portions of the western army. One of the reasons the siege of Antioch took so long was that the crusaders had no siege machinery, a fact that made laying siege to the massive city of Jerusalem problematic. After surrounding the city, however, the Crusaders fortuitously located timbers with which to construct siege towers. They used these towers to enter and reduce the city in July of 1099. One month later, they won the final crucial battle of the First Crusade not through grinding siege warfare, but through a surprise attack. Their attack, which came at daybreak in the town of Ascalon on August 12, destroyed an Egyptian army that had come to relieve the inhabitants of the city.