From Texas Standard:
Fransisco Antonio Ruiz was there.
He was an eyewitness, as the alcalde – or mayor – during the siege of the Alamo. While the siege was going on, Ruiz's father, José Fransisco Ruiz, was 150 miles to the east at Washington-on-the-Brazos, where he represented San Antonio as a delegate to the convention that formally declared Texas' independence.
In an account published in the 1860 Texas Almanac, Antonio Ruiz said that the Mexican army, under the command of López de Santa Anna, arrived on the afternoon of February 23, 1836. That very evening, an exchange of gunfire began.
Early on the morning of March 6, Mexican forces, which Ruiz estimated to number 4,000, advanced for a final assault of the Texan rebels. The very morning the Alamo fell, Ruiz said: "Santa Anna directed me to accompany him, as he was desirous to have Colonels Travis, Bowie, and Crockett shown to him."
Santa Anna then ordered him and other townspeople to carry the Mexican dead soldiers to the local cemetery. Back at the Alamo, Santa Anna next directed Ruiz to take a company of Mexican soldiers and bring wood with which to burn the corpses of the defenders.
The grisly details remained in Ruiz's memory for the rest of his days.
"I was an eyewitness," Ruiz wrote. "For as the alcalde of San Antonio, I was with some of the neighbors collecting the dead bodies, and placing them on the funeral pyre."