The article quotes the letter as follows:
Dear Derek (Shaw),
I am writing to apologise to you personally and to your Board, as well as most importantly your fans who were the subject of disgraceful and frightening behaviour after the game.
We are looking into what happened and to what extent there were 'external trouble makers' inciting that behaviour. But we are not looking for excuses.
Let me assure Preston fans that we have had no incidents like that since we opened the Ricoh Arena over 2 years ago. We pride ourselves on the warm welcome we extend to all visitors, and we'll put it right next season.