This dream is what lead me to this website a few minutes ago. This is what happened.

It was set at a few years prior to the present time as I remember various people in the dream that I knew a few years ago.
We were inside a house, seemingly owned by a grandmother of one of my companions. The grandmother made her presence known eventually.
Towards the end, a frisbie was thrown onto the roof of the house. It landed on a patch of the roof that just happened to be a window, and of course I just happened to be under the window. Being able to see where the frisbie landed, I announced its position to my companions.

At this point, all of a sudden I heard a siren, a very loud siren. Immediately, I saw everyone sprint out of the house.
--
This part is what bugs me. It was my understanding that while dreaming, the logic and reasoning centers of our brains tend to be turned off. Under this assumption, what happens next is very counter-intuitive.
--
Initially, I had no idea what was happening. I witnessed the siren and all my companions escaping the house. Not until a couple seconds later did it hit me, it was a bomb siren. Then of course I followed them out of the house and laid down next to the wall they were all huddled up against. The wind began picking up, as I slowly inched my way to the edge of the wall and stood up. At this point, I had regained enough command over logic to use the sun to determine which direction I was facing, it was North. The air felt warm as it whipped through my clothes and as I slowly stood up, I was greeted with the scenery of two nuclear explosions in the distance to the North.
------------

Now, the first part that unsettles me is the fact I managed to figure out the siren was a bomb siren. If dreams are supposed to be lead by our own thoughts, then we should have some kind of premonition as to what will happen next. This is how it has always been for me anyways. But this dream was different, I had absolutely no idea it was a bomb siren. And I most certainly would have made no connections of it to a bomb siren if I had not witnessed my companions fleeing the house in droves.

Secondly, did my realization of the siren to be a bomb siren change it into a bomb siren? Consequently did my realization of that also cause the nuclear explosions afterwards?