Over 15,000 chickens are being destroyed by Tyson Foods in Springdale after exposure to a strain of avian flu was found in some of their birds. State and Federal Poultry Inspectors found the strain during blood tests late last week and Tyson began destroying some of the infected birds immediately. John Fitch with the Arkansas Livestock and Poultry Commission says none of the birds were actually infected with avian flu, but some have been exposed to a sub strain of the virus. Fitch says there is absolutely no human threat, but the possible exposure is something the commission takes very seriously so all precautions are being taken.