Sadly, this is just an urban legend. It originated on IMDB as unsubstantiated trivia. It is true that he had to do a moment of silence in the turtle suit, but this was weeks after 9/11.
But there were scenes in 28 days later filmed on 9/11, and apparently the tragedy entirely reshaped the movie.
Also Francis Ford Coppola had a second-unit camera team filming in NYC that day, which is where some of the higher quality footage comes from.
Sadly, this is just an urban legend. It originated on IMDB as unsubstantiated trivia. It is true that he had to do a moment of silence in the turtle suit, but this was weeks after 9/11.
But there were scenes in 28 days later filmed on 9/11, and apparently the tragedy entirely reshaped the movie.
Also Francis Ford Coppola had a second-unit camera team filming in NYC that day, which is where some of the higher quality footage comes from.