A hastily convened council of war voted to evacuate the area and retreat. The evacuation commenced at midnight and happened so quickly that many Texian scouts were unaware the army had moved on. Everything that could not be carried was burned, and the army's only two cannon were thrown into the Guadalupe River. When Ramírez y Sesma reached Gonzales the morning of March 14, he found the buildings still smoldering. Most citizens fled on foot, many carrying their small children. A cavalry company led by Seguín and Salvador Flores were assigned as rear guard to evacuate the more isolated ranches and protect the civilians from attacks by Mexican troops or Indians. The further the army retreated, the more civilians joined the flight. For both armies and the civilians, the pace was slow; torrential rains had flooded the rivers and turned the roads into mud pits. As news of the Alamo's fall spread, volunteer ranks swelled, reaching about 1,400 men on March 19. Houston learned of Fannin's defeat on March 20 and realized his army was the last hope for an independent Texas. Concerned that his ill-trained and ill-disciplined force would only be good for one battle and aware that his men could easily be outflanked by Urrea's forces, Houston continued to avoid engagement, to the immense displeasure of his troops. By March 28, the Texian army had retreated across the Navidad and Colorado Rivers. Many troops deserted; those who remained grumbled that their commander was a coward. On March 31, Houston paused his men at Groce's Landing, roughly north of San Felipe. Two companies that refused to retreat further than San Felipe were assigned to guard the crossings on the Brazos River. For the next two weeks, the Texians rested, recovered from illness, and, for the first time, began practicing military drills. While there, two cannons, known as the Twin Sisters, arrived from Cincinnati, Ohio. Interim Secretary of War Thomas Rusk joined the camp, with orders from Burnet to replace Houston if he refused to fight. Houston quickly persuaded Rusk that his plans were sound. Secretary of State Samuel P. Carson advised Houston to continue retreating all the way to the Sabine River, where more volunteers would likely flock from the United States and allow the army to counterattack. Unhappy with everyone involved, Burnet wrote to Houston: "The enemy are laughing you to scorn. You must fight them. You must