On a hot July day in 1996, a Boeing 747 carrying 230 people departed New York’s John F. Kennedy International Airport on a flight to Paris, France. The aircraft experienced an uneventful takeoff and initial ascent, but only 12 minutes into the flight, a sudden and catastrophic explosion in the center wing fuel tank tore the fuselage apart, raining debris into the Atlantic. All passengers and crew members lost their lives. National Transportation Safety Board (NTSB) investigators needed four years to retrieve the wreckage, reconstruct the aircraft and determine the probable cause. In its official report, the NTSB concluded that excess energy entered the center fuel tank through a short circuit in external wiring. Then, a latent fault on probes inside the tank most likely caused an electrical arc that ignited the flammable fuel/air mixture, leading to the explosion and structural failure. The 230 passengers and crew on Flight 800 paid the ultimate price when the accident exposed flawed assumptions regarding aircraft design practice. This study details those assumptions and emphasizes the need to continually re-evaluate our projects and equip our systems with additional layers of safety to protect against wrong assumptions and unanticipated failure modes.