Abstract: On April 7, 2012, Employee #1, #2, #3 and #4 had been working at a call center. Employee #1, who was an emergency phone operator, had worked the previous day and began feeling ill around 8:00 p.m. with symptoms of headaches, dizziness, and lightheadedness and went home sick. On the next day, which was April 7, 2012, Employee #2, #3 and #4 started the midnight shift. While beginning their work, they started feeling ill as well, experiencing headaches and lightheadedness. The employees were concern about their health and reported the condition to their management. Management decided that the employees should be moved into a training room and work from there, until the problem was looked into; however, the phones were not properly hooked up to the phone call system, so the plan was abandoned. The employees continued to work in the call center to around 4:00 a.m., when the employees' conditions worsened and requested to be taken to the hospital to be evaluated. Employee #1, who had gone home sick from the previous day, heard about the working conditions and requested and was allowed to be seen at the hospital. All four employees went to the hospital to be evaluated. A local OSHA industrial hygienist responded to alleged hazardous condition at the facility. Multigas detector meters (Model Types ToxiRae PID) were used to evaluate the air condition. No organic compound readings could be found on the meter in the workspace. The detector read 0.00 parts per million of carbon monoxide, hydrogen sulfide, and methane gas with 20.3% oxygen levels in the workspace. There were no other odor or other potential atmosphere components detected by the meter. The industrial hygienist was informed that a pump room had had an active water leak where sewage was being spilled onto the ground. The industrial hygienist identified this room as the "Fire Riser Room" and entered it. A sewage line was in the room and there was a small amount of visible liquid on the ground with a faint odor of sewage in the air. The industrial hygienist was told that the pipe had been damaged and was recently repaired. Engineering staff operated the pump switch. The industrial hygienist noted the plumbing repair was not done properly and some raw sewage spilled onto the ground. The gas detector meter continued to read 0.00 ppm of hydrogen sulfide. The entire property was walked but no readings were observed to register on any device. The industrial hygienist noted finding several dead roaches throughout the property and commented the vermin control was an issue at the call center. A plumbing contractor was seen entering the building to fix the plumbing issue when industrial hygienist was leaving. A follow up site visit was conducted and was unannounced. The atmosphere within was building was sampled and no hazardous components were present. An employee commented that no further issues had come up in the call center, which were similar to the previous event. During this surprised site inspection, the sprinkler riser room was checked and the plumbing had been repaired. There were more dead roaches found in that room and throughout the call center.