Here's a Theory that would be either soon happen in the future or not. (And probably, if some would make a novel out of the theory, be a intresting setup of looking through the grim future. Like Orwell's 1984, only taking place in 2046.)

15 Years after 9/11, The world is not recovered from the tragedy of 9/11 as it gets worse and worse within the years as police brutalities, massacres, homicide, rape, suicide along with terrorist attacks getting worse than ever before.

And pretty soon there might be another 9/11...

in 2021.

If we don't stop those acts of horrible crime, there will be a 9/11 2021 attack and would be even worse than the previous one.

I will think that 350,000 people would be slain, beheaded, gunned or executed to death by many terrorist organisations in 9/11/2021 along with the US losing more than 12 countries in 5 states, including new york.

And pretty soon after that event in the future, WWIII would begin and it will last even longer than the previous world wars (Think 25 years.) and will take the lives of 5 billion people (which is almost half of the world population killed off from the planet.)

And also in the future, during the 25 years, we will see the 7 big brothers that were elected during WWIII that representing the seven deadly sins.

Pretty soon, the world would become worse than the Post-Columbine/9/11 world in the future.

But hey, it's only a theory that would happen in the future, or not.