Abstract: At approximately 1:30 p.m. on June 10, 1996, Employee #1, 44 coworkers in the records, accounting, and procurement departments, and one coworker in the reception lobby, noticed a foul odor that many claimed caused eye, nose, and throat irritation. All these departments except for the lobby were serviced by the same HVAC unit and had common ducting. The lobby was serviced by a separate unit. Shortly after the odors were reported, Employee #1 and the other 45 coworkers were sent to local medical facilities as a precautionary measure. Two employees were monitored further because of preexisting health conditions--one was pregnant and the other was an elderly woman--while the others were treated and released. Subsequent investigation revealed that Southern California Edison had been repairing a natural gas leak near the HVAC system. It is believed that the affected employees were exposed to elevated levels of natural gas that entered the shared ventilation system during the repair. At the time of the inspection, there were no lingering odors and no additional complaints were made after the incident. The employees returned to work and did not experience any ongoing problems.