Over 30, 000 people have written in so far -- as many as 2, 000 every hour.

WHITEHOUSE: President Obama Speaks on the Importance of Extending the Payroll Tax Cut | The White House

According to Bowker's Books in Print database, which tracks print and e-books published and distributed in the United States, 164 such works have been written so far - they either directly address the event or use it as a peg to hang greater literary concerns about love, life and loss.

BBC: Is there a novel that defines the 9/11 decade?