There is now no back-up to the supply that the hospitals have on hand. We have issued virtually all of the blood on our shelves, and urge healthy individuals to donate blood now.

We are now at a point where patients across the county are at risk. There is no safety net.

We can't emphasize enough how dangerous this shortage has become. We are fortunate that there weren't more serious injuries in the sign collapse on Interstate 805 yesterday, and that blood was not needed.

Though many donors have responded to this emergency, the amount of blood needed to rebuild the supply far outweighs donations.

We understand that the Louisiana attorney general is investigating all deaths that occurred at New Orleans hospitals and nursing homes after the hurricane, and we fully support and are cooperating with him.

In the case of emergency angioplasty, for hospitals it seems that it's not just how many you do, but how used to doing them you are. The overall commitment to doing emergency angioplasties, and the protocols and staffing that come out of that commitment, appear to be key.