two almost linked dreams

Last November, on the 27th or 28th, I had a strange dream that my school was attacked by terrorists, and we were all besieged in the main hall, in almost identical conditions to the beslan school attack.
exactly six months later, I had a dream about it again, but this time it was at a diferent stage, and it was either at break or at the start of a school day, and bombs went off in different corners of the school, and we were herded into the main hall, and the dream ended at much the same point as the first had started.

It seemed quite strange to me that the second was exactly six months after the first.