What does my dream mean?

Pretty much there was some nuclear explosion that was going to happen or something. So the local government/martial law put me and other people into a warehouse type place. We were told that the radiation would get to us in the middle of the night while we slept and if anybody survived, they were to report to a military base type place. So apparently this happened before and I was one of the few survivors from the last time so I went in the same corner of the building that I went last time (memories were conceived in dream) and fell asleep on the concrete among many others. I awoke in the middle of the night cold and found some sheets of metal and covered myself with to stay warm. (and somehow saved me) I then woke up in the morning and everyone died in radiation except me and some guy. As we left the building the dream ended.