"For months, the DaVita Dialysis Center in Lufkin, Texas, had been baffled by the rising number of deaths and injuries occurring in their clinic. In April alone, they'd rushed thirty-four patients to the hospital. But no one expected such a horrific cause to be behind it all. Kimberly Clark Saenz was a well-liked licensed vocational nurse at the center. The East Texas nurse was a mother of two, and known for her smiles and the stories she told to...