Answer:
What I heard was that people in the science laboratory in china "accidently" let loose a virus that they were studying, which also led to that person in contact with it to go out and spread it without knowing. Causing the virus to spread across all the world within a few months.
That is my explanation! \_(ツ)_/
The organization Al Qaeda led by Osama Bin Laden was the perpetrator of 9/11
What am I supposed to be answering?