The crusaders and Venetians, incensed at the murder of their supposed patron, demanded that Mourtzouphlos honour the contract that Alexios IV had promised. When the Byzantine emperor refused, the Crusaders assaulted the city once again. On 8 April Alexios V's army put up a strong resistance, which did much to discourage the crusaders. The Byzantines hurled large projectiles onto the enemy siege engines, shattering many of them. Bad weather conditions were a serious hindrance to the crusaders. A fierce wind blew from the shore and prevented most of the ships from drawing close enough to the walls to launch an assault. Only five of the wall's towers were actually engaged and none of these could be secured; by mid-afternoon it was evident that the attack had failed.