We were told to close all doors and windows and wait for the police to come and were exploring how we would feel were we plunged into that situation.
In fact, during the course of the day we got so into our characters and the situation that fellow students, coming in just to watch for a few minutes, could not tell when we were acting and when we were not.
At the end of the day we went over what we had created and were filmed by cameramen and had photographers taking pictures for local papers.
What made what we were doing so interesting and hard-hitting was, for us, the fact that an incident like that could happen at any time.
And, before today, I had no idea that there were nuclear trains let alone the consequences of one crashing."
Ahmed and Robert, 15, Hampstead High School
Why don't you write us a Press Pack report - and get it published on the site?!
It can be about anything that's happened in your local area - or your views on the news.