In September 2009, a fatal incident occurred in a cryogenic gas processing plant. The investigation of the incident indicated a number of potential issues that may have contributed to or caused the event. These issues include hot work procedures, electrostatic discharge, electrical conduit sealing, convective "breathing" due to multiple vents, equipment age, maintenance, and worker training. The investigation concluded that the fuel for this event was provided by small leaks from the product pipes inside of the cold box; the oxygen was provided by convective "breathing" that occurred due to the presence of two vents from the cold box and the erosion of the flapper valves that were intended to seal these vents; and ignition occurred due to stray currents that resulted from poor hot work procedures, and locating the return lead far from the work location. This article provides an overview of the process and facility, a timeline of events, a summary of the investigative process, and a discussion of the lessons learned from this event. (C) 2015 American Institute of Chemical Engineers