Belinda Caminada reports from Hong Kong on today's slaughter of more than 1.3 million chickens, ducks, geese and pigeons in an effort to eradicate a mysterious flu linked to poultry that's killed four people. The H5N1 virus has long been known to infect birds, but jumped to humans for the first time this year. Thirteen cases in humans have been confirmed, including the four people who died. Officials say no poultry will be sold in Hong Kong unless certified as safe. So far, no one's saying when that will be.