The 1918 influenza virus that killed more than 20 million people worldwide is unlike any virus ever seen. The Influenza A strain of the virus is the most serious and deadly strain of the flu viruses. Researchers say that this virus resides harmlessly in birds, where they are genetically stable. A bird may infect another animal, usually a pig, and causes the virus to change genetically to survive. This results in the deadly virus we call the "Spanish flu," (the flu virus of 1918) that once killed so many people. When this strain of the flu spreads to humans, it can be devastating.

Although the disease that caused the worldwide epidemic in 1918 was called the "Spanish flu," the virus apparently is a mutation that evolved from pigs and was spread around the world by Americans troops during WWI. An American private, whose preserved lung tissue was analyzed, contracted the flu at Fort Jackson, South Carolina. Traces of the virus were also found last year in the frozen bodies of Americans in an Inuit village in Alaska. Their bodies were recovered in permafrost in a mass grave about one meter below the surface. These remains help support the worldwide theory that the flu virus from swine is the most damaging in humans. It killed a total of 700,000 people in the United States alone, nearly a quarter of the nation's population.

Unlike most flus, the Spanish flu hit the youngest the hardest. Scientists speculate that the elderly, usually the hardest hit, may have built up an immunity from a varity of similar viruses in the late 19th century. Researchers say that this epidemic could strike again, but with new technology, hopefully, we can stop it before it really spreads.

The more I researched this topic, the more I found a difference in facts and opinions. This set of facts I found may not be exactly what happened. For more information, I suggest you look up and research this topic, and you can then judge for yourself.