Sometimes people have "unusual dreams" called "Nightmares". Many will remember them and others not, but that you saw stays inside your head, when you wake up and you feel nervous and insecure even in your own home, afraid to actually happen to you what you saw in your dream.
Many people do not believe in nightmares, because the think they are pure nonsense. Others wonder if they really are some signals. But what I can assure you is that for 6 teen-agers was not just a nightmare... It was a total nightmare come true!