Yvonne, the plans (from the URL you mentioned) are quite inspirational. In their list of things they wanted to achieve, it was truly taking something negative and turning it around into something quite positive. Taking down former barriers, linking places together, etc. I'm thoroughly impressed with their goals. And they weren't dwelling on what caused it, but rather how to gain from the opportunity to do something right.
I know my 2p thought is tiny compared to the gajillions who also have emotions and things to express. I'd just want a nice memorial done remembering the people and heros, not even giving one slight mention as to what caused the tragedy.