Cortes, finding at length that it was impossible to fill up all the canals, gaps, and openings in the causeway, and that the Mexicans always destroyed at night what we had completed in the day, reopening the apertures we had filled up, and throwing up new entrenchments, called the principal officers of his division together, to deliberate on the present state of the siege. He told them the men would not be able to continue this fatiguing mode of warfare much longer, and he therefore proposed to them that the three divisions should fall upon the city at the same moment, and fight their way up to the Tlatelulco, and there encamp with the troops. Cortes at the same time wrote to Alvarado and Sandoval, desiring them also to deliberate on this point with their officers and soldiers. From that place, he added, they would be able to attack the enemy in the streets, and not have to encounter such severe engagements, or make those dangerous retreats every evening, nor have everlastingly to toil in filling up the openings and canals. As it always happens in such cases, opinions were very different. Some pronounced this plan to be altogether unadvisable, and were for pursuing the present plan of operation, which was, to pull down the houses as we advanced, and fill up the openings. Those of us who were of this opinion gave as our principal reason for so thinking, that if we fortified ourselves in the proposed way on the Tlatelulco, the causeways must fall into the hands of the Mexicans, who, with the vast number of men at their command, would undoubtedly reopen the hollows we had filled up, and make other fresh apertures in the causeways. In this great square we should night and day be assailed by the enemy; while our brigantines would not be able to come to our assistance, on account of the stakes driven in the water. In short, we should be surrounded on all sides, and the Mexicans would be masters of the town, of the lake, and of the surrounding neighbourhood. This, our opinion,[23] we took care to draw up in writing, to avoid a recurrence of what took place on our unfortunate retreat from Mexico. Cortes indeed listened to our reasons for objecting to his plan, but nevertheless determined that the three divisions, including the cavalry, should make an attempt on the following day to fight their way up to the Tlatelulco, and that the Tlascallans, with the troops of Tezcuco, and of the towns which had recently subjected themselves to our emperor, should cooperate with us; the latter were more particularly to assist us with their canoes. The following morning, accordingly, after we had heard mass, and commended ourselves to the protection of God, the three divisions sallied forth from their respective encampments.