Your grandfather and about 70 million other people. Now here is what is interesting about that particular strain now that we actually know its genetics. It killed healthy people as well as the young and old, which WAS a very scary fact.

However...

This is neat. We have acutally determined that this flu virus killed people by causing an autoimmune reaction. It directed the bodies defense system to attack itself, kinda of like the disease Lupus. And we also know how to stop this reaction from occuring in the case of this old flu virus. So if one of these particular strains arose again, there are some drug companies that would make big money off of the reagents that stop this autoimmune response. And the bottom line is it would probably not kill near as many healthy individuals or more susceptable folks.