I see a lot of alt history where 9/11 happens even when it wouldn't make sense given the changes so actually I applaud the OP here for contra-historically preventing it
i like to imagine 9/11 as a fixed point where no matter what happens in world history, at some point people start building two towers in new york and then they fall down on september 11th
What if instead of being attacked with hijacked planes the WTC had been struck by the wrath of Poseidon? Terrifying thought. Imagine how many more people would have been killed. We should tell the people who lived through 9/11 but would have been killed if they had faced the vengeance of the God of the oceans to be thankful to al Qaeda. It could have been so much worse.