Urrea called on Filisola to continue the campaign. He was convinced he could challenge the Texan troops. Hardin said: “Santa Anna had made a military disaster in Mexico; Filisola didn`t want to risk anyone else.  Spring rains ruined the ammunition and made the streets almost impassable, with the troops kneeling in the mud. Mexican troops quickly emerged from food, and began to contract dysentery and other diseases.  Their power lines completely collapsed, so there was no hope of strengthening.  Filisola later wrote, “If the enemy had met us in these cruel circumstances, on the only path that remained, there was no alternative but to die or surrender to his discretion.”  In the early morning hours of March 6, the Mexican army attacked the fort.  Bexar`s troops were excused by the front lines for not being forced to fight their families and friends.  In the early moments of the attack, Mexican troops were at a disadvantage. Although their columns only made it possible to safely fire soldiers, inexperienced recruits in the back also released their weapons; Many Mexican soldiers were killed involuntarily by their own comrades.  When Mexican soldiers crossed the walls, at least 80 Texans fled the Alamo and were knocked out by the Mexican cavalry.
 In one hour, almost all Texan defenders, estimated at 182-257 men, were killed. [Note 12] Between four and seven Texans, including Crockett, appeared. Although General Manuel Fernandez Castrillén tried to act for me on his behalf, Santa Anna insisted that the prisoners be executed immediately.  Many Mexican soldiers retreated through the marsh to Peggy Lake. [Note 15] Texan snipers deployed on the banks and shot at anything that moved. Many Texas officers, including Houston and Rusk, tried to stop the massacre, but they were unable to take control of the men. The Texans continued to chant: “Remember the Alamo! Remember Goliad! “While the frightened Mexican infantry shouted “Me no Alamo!” and asked in vain for mercy.  In what historian Davis described as “one of the most one-sided victories in history,” 650 Mexican soldiers were killed and 300 captured.  Eleven Texans died and 30 others, including Houston, were injured.  Cos received 650 reinforcements on 8 December, but to his dismay, most of them were brute recruits, including many inmates still in chains.  Instead of being useful, reinforcements were primarily runoff to reduce the food supply.  On 9 December, when cos and most of his men saw few other options, he recalled the Alamo mission on the outskirts of Bexar.
Cos presented a counter-attack plan; The cavalry officers thought they would be surrounded by Texans and declined their orders.  Perhaps 175 soldiers from four cavalry companies left the mission and went south; Later, Mexican officers claimed that the men had misunderstood their orders and had not deserted.  The next morning, Cos gave himself.  Under the conditions of surrender, Cos and his men would leave Texas and no longer fight against the supporters of the 1824 Constitution.  With his departure, there was no longer an organized garrison of Mexican troops in Texas and many Texans believed that the war was over.  Burleson resigned as head of the army on 15 December and returned to his homeland. Many men did, too, and Johnson took command of the remaining 400 soldiers.  General Cos was one of 730 Mexican soldiers captured at the Battle of San Jacinto. After his surrender, he was released to Mexico and to an obscure military post in Tuxpan.