Check out the 9-11 Remembrance Archive of posts from that day and you'll see that Fox did speculate it might be deliberate, but Freepers were way ahead of Fox and pinned it on OBL within minutes.
http://www.freerepublic.com/focus/f-news/620413/posts
that is because Rita Cosby had to finish he donut and read posts on FR before she came on and said her "sources" said OBL might be involved.