A photograph by Brandon Bell, distributed by CNN, shows fifteen beefy men in military caps and fatigues, standing in front of a chain-link fence on a concrete boat ramp. It is evening in Shelby Park, the city park of Eagle Pass, Texas. The frigid water of the Rio Grande flows just footsteps away. On the other side in the distance is a riverbank: Mexico.

It was here in the dark, on January 14, that Victerma de la Sancha Cerros, a thirty-three-year-old mother from Mexico City, stepped into the water holding the hands of her two children, ten-year-old Yorlei Ruby and eight-year-old Jonathan Agustín Briones de la Sancha. We don’t know how they got into trouble in the strong current or if they even knew how to swim. Grupo Beta, Mexico’s border rescue service, saw them struggling and called the US Border Patrol. Agents went to the park gate, a couple of miles from the boat ramp. The beefy men in fatigues, soldiers of the Texas Military Department (TMD), refused to let them through.

Mexican authorities tried to rescue the mom and her children but were only able to save two others. The three drowned, and Grupo Beta could only return to Mexico with their bodies. Later the TMD said its soldiers, standing behind their chain-link barrier, had shone high-powered lights on the water and used their night-vision goggles, but somehow had seen nothing.