The Exercise below
While I personally do not believe we are looking at a pandemic of the magnitude described in the fictional scenario below, I offer this as an example of the difficult decisions that might have to be made in the face of a pandemic.
A more likely scenario would be for a pandemic like we saw in 1918, where 30% of the country contracted the illness, and perhaps 5% of those died.
However, to date, the CFR (case fatality rate) of the Avian Flu has run over 50%. No one knows if it will decrease in its lethality if it should turn into a pandemic.
So the little exercise below is not beyond the realm of possibilities.