If you’re worried about the possibility of a coming bird flu epidemic, you can take comfort in the fact that humanity has survived a similar influenza epidemic in the past. Starting its rounds at the end of World War I, the 1918 flu killed an estimated 50 million people. It killed more people in a year than the Bubonic Plague, and in its more than a year of existence killed more people than AIDS did in 25 years.

Popularly known as the Spanish Flu, this strain of influenza was far worst than your common cold. Normally, influenza only kills those who are more vulnerable to disease, such as newborns, the old or sick. However, the Spanish Flu was prone to killing the young and healthy. Often it would disable its victims in hours; within a day, they would be dead, typically from extreme cases of pneumonia. Unfortunately, this quick death was not enough to keep the disease from spreading all over the world.

The Spanish flu was quite nasty – fast-spreading and deadly. The Spanish Flu managed to spread across the globe, devastating the world. Then suddenly, after two years ravaging the Earth, it disappeared as quickly as it had arose.

Despite its nickname, the Spanish Flu did not originate in Spain. Its true origins are unknown, but there are a few theories that virologists have proposed. Some believe it started in US forts and then spread to Europe as America joined the war; others think that it populated the trenches of the English and the French and eventually broke out in 1918. Regardless of where it started, eventually a fifth of the world population suffered the disease, with a global mortality rate estimated at 2.5% of the population. Within the US alone, 28% of the population is said to have suffered the disease.

Modernity is partly to blame for the quick spread of the disease. It passed throughout the world on trade routes and shipping lines. It hit Northern America, Europe, Asia, African and the South Pacific. The war did not help at all – the movement of supplies and troops aided the spread of the Spanish Flu, as well as the trench warfare. Imagine the speed at which a virus can spread in a crowded ditch. The fast emergence of the virus in the trenches caused some soldiers to believe that the Spanish Flu was a new form of biological warfare.

The Spanish Flu changed people’s ways of life. Gauze masks were publicly distributed. Flu ordnances were passed to help quarantine the disease. Some towns required special paperwork to pass through them. Funerals were limited to 15 minutes in length. Hospitals became filled so quickly that there were not enough doctors, so medical students were forced out of school and into hospitals as nurses or interns. Of course, there was a grave shortage of coffins, morticians, and gravediggers.

Luckily, the Spanish Flu simply vanished by 1920. It is believed the flu simply ran out of fuel to spread. The scoreboard: Humanity, 1; Flu, 50,000,000.

In recent times, scientists have managed to find reproduce strains of the Spanish Flu from the dead found in permafrost from 1918 and are testing its affects on mice. This is a dangerous undertaking – some scientists did not want anyone to do it, sure that the Spanish Flu would have another (and this time more deadly) outbreak on the world. Thankfully this has not happened, and the results have useful for our current situation, since the original strain is now believed to have come from birds. As such, studies are now being conducted to see how the 1918 flu mutated from a bird flu to one that could pass between humans. Hopefully, some studies will find ways to create an effective vaccine before any future bird influenza destroys the world population.