Fearing for the safety of his wife's relatives in San Antonio, Bowie invited her cousins Getrudis Navarro and Juana Navarro Alsbury, as well as Alsbury's 18-month-old son, Alijo Perez Jr., to stay inside the walls of the Alamo. Bowie also brought several black servants, some of whom worked at the Veramendi Palace, into the security of the Alamo fortress. Bowie had been ill, and two doctors, including the fort surgeon, were unable to diagnose his illness. Travis became the sole commander of the forces when Bowie was confined to bed. Santa Anna and his army began a siege of the Alamo on February 24. The Mexican army raised a red flag to warn the defenders that no quarter would be given.