What started the Black Plague in the first place is when ships arrived from Asia, rats that were on the ships because of the food crates carried fleas on them. And those fleas got onto the people which basically had no CHANCE of survival. They got things such as boils, black finger nails, etc. And then... they died.
Just like this poor woman, people were thrown into the streets!
The black plague spread across Europe, eliminating 45-50% of its population! People tried burning the dead bodies, thinking it spread by people. But little did they know...
And after the tragedy that took place, people were different. They didn't CARE about life in the future(heaven), they cared about life NOW. And it lead to amazing stuff made by people, such as myself, Leonardo da Vinci, etc. The printing press was invented... And people lead new lives. The end.