I was just visiting the Sun online news looking for Victor Meldrew in Spac (UK residents will understand) when I saw an interesting article.
An online game has been created regarding the events of 7/7
It has a screen of the official London Underground map with trains going across the tracks while timed bombs are connected to the trains. You have to blow up the bombs before the bomb explodes and sirens are heard.
Maybe it is irresponsible and childish to make this game but it was made in memory of the victims of the 7/7 attack.

Enjoy

Article
Play the game