There have been many terrible sicknesses that have harmed human beings. There was MERS, Ebola, and Avian Influenza just to name a few. Luckily the scariest and deadliest killer of all has not come back. In the history of human beings, there was a sickness that killed 200 million people. It is known as the "Black Killer" or more commonly known as the Bubonic Plague. Scientists as still not sure what kind of bacteria really started the Black Death until 2010. They discovered that the original bacteria changed from not dangerous to a killer. According to history, the Black Death first started in the 13th century, Central Asia . The bacteria were carried by fleas. The fleas infected people by biting them. While the fleas carried the bacteria that
