On December 23, 2003, a gas-well blowout near the city of Chongqing in central China released a deadly mixture of natural gas and hydrogen sulfide. The toxic cloud of â€œsour gasâ€ killed 243 people, caused the hospitalization and treatment of more than 9,000 and the evacuation of more than 60,000 nearby residents. Only two of those killed were gas field employees. The rest were residents of the surrounding area.
The nighttime accident was Chinaâ€™s worst oilfield disaster. The toxic cloud slowly drifted across villages, killing people in their beds or in fields or roads as they tried to flee, leaving behind what authorities described as a ten-square mile â€œdeath-zoneâ€ downwind of the blowout.