We investigate the 1918 Spanish Flu, and compare it with older and newer flu pandemics, including the latest information on the current Covid-19. The Spanish Flu was unusual in killing mostly young and healthy adults, as opposed to more common influenzas, that cause mortality among newborn or the old and infirm. The Spanish Flu could strike suddenly, and rendered victims too feeble to walk within hours. Many would die the next day. The Spanish Influenza killed a high proportion of 20 to 40 year old's. Covid-19 mostly affects those over the age of 65, especially those with pre-existing illnesses.