During the siege, Hartmann of Dillingen and Henry of Esch spent a lot of time and money on a siege-engine to protect those undermining the wall, but they finally failed: it was crushed by stones from above and overbalanced, with heavy casualties. An Apulian engineer was more successful, allowing the undermining of the wall, but leaving the fortification still defensible. An attempt to widen the breach was unsuccessful. A major problem to the attackers was the lake of Nicaea, which allowed Kilic Arslan to supply the defenders unhindered. Alexios stopped this by providing ships, which the crusaders dragged on carts from the sea at Kios to the lake. Under the command of Manuel Boutoumites, they were manned with fully-armed soldiers, and provided with excess flags, trumpets and drums, to give a false impression of their numbers; they cut off access from that side of the city. Tatikios and Tzitas landed from boats at Hagios Georgios and rode up to Nicaea with a huge supply of arrows. They joined combined assaults under western command, covering the crusaders with a heavy shower of arrows. Alexios also provided siege-engines of his own design. Raymond of Toulouse concentrated his siege-engines on the tower of Gonatas where Kilic Arslan's wife, sister and children were said to live. They were terrified and tried to escape from the siege via the lake, but were captured and handed to Alexios. Godfrey of Bouillon's men suffered from an accurate and abusive archer, who killed many of them till Godfrey himself killed him with an arrow, to discourage any more such effrontery. Prominent crusader casualties included Baldwin Chauderon, Baldwin of Ghent, Galo de Insula, Guy of Possesse and William of Forez