Approximately 3００ people at a chicken processing plant in northwestern Arkansas, USA had to evacuate the building on June ２７, ２０11 after a mixture of chemicals used on the meat released potentially deadly chlorine gas in the facility, sending 1７3 to local hospitals with at least one in intensive care.

http://www.sfgate.com/cgi-bin/article.cgi?f=/n/a/2011/06/28/national/a180001D33.DTL,
http://www.claimsjournal.com/news/southcentral/2011/06/30/187719.htm
http://www.msnbc.msn.com/id/43570486/ns/us_news-life/
http://gamutnews.com/２0110628/40648/video-tyson-gives-update-on-chlorine-leak.html
http://ehstoday.com/fire_emergencyresponse/news/tyson-workers-hospitalized-chlorine-gas-leak-0629/