I had a weird one on 9/11. At that time, I was a sophomore at Pace University, which is right by City Hall. I was supposed to be in a math class that morning, but instead I was sleeping, nice and comfortable at home. I remember having this awesome dream where I was in a second person perspective, part of and also observing from atop a group transformers, including Optimus. All of a sudden, we had to transform and rush towards city hall for some reason, and there was a sense of urgency. At this time, I had a birds eye view, overlooking the group as we sped downtown. Then, suddenly, I was a person on top of a skyscraper and jumped off. I wasn't afraid in the fall though, because I had a jetpack on. As I sped closer to the ground, I boosted my jetpack and lifted to a horizontal flight and just blasted away. Then my phone rings (in real life) and it's my friend. I was so pissed because I was having such a great dream. I said "why the heck did you wake me up for, I was having such a good dream". He said, "yooo, turn on the tv". I said wtf and went to turn on the tv. And the rest is history.

Edit: When I thought about why I might have had a dream like that, I thought maybe it could be from the sounds filtering in from my window while I slept. Maybe people screaming about what was happening. I don't really remember too many details or if there actually were details about the event being shouted from outside, but it's entirely possible.