San Antonio arts nonprofit Luminaria has unveiled a mural honoring the 53 lives lost when an 18-wheeler carrying undocumented migrants was abandoned on the South Side during a sweltering summer day two years ago. The new artwork, located in the South Side’s Mission County Park, was dedicated Wednesday morning during a ceremony attended by Bexar County Commissioner Rebeca Clay-Flores and Yadhira Lozano, Luminaria’s executive director.