Abstract: At approximately 5:57 p.m. on February 3, 2017, an employee was working in the crawl space of Tower B to unclog food sink drains underneath the facility's kitchen. Workers were working in confined space in Mechanical Room Number 5. They were tasked to unclog four food drains which were located 50 to 60 feet from the confined space entrance. The employee exited the confined space before the two additional coworkers that were still working in the confined space. The employee sat on a bucket after exiting the confined space and began having trouble breathing and collapsed. Medical staff was called by BCSO maintenance technician and cardiopulmonary resuscitation was administered. The employee was transported to the Downtown Baptist Hospital and was pronounced dead at 7:31 p.m. During his work task, the employee was wearing a full Tychem suit, an N-95 respirator, rubber boots, headlamp, and a hardhat. An assessment was performed by the San Antonio Fire Department after the employee was removed from the area and 8.5 ppm Hydrogen Cyanide was detected in the room near the entrance of the confined space. The company did not have a respiratory protection program or confined space program. The autopsy findings indicated that the employee had a pre-existing health condition which could have been exacerbated by respirator use.