In Shock.
White House Chief of Staff Andrew Card whispered in the president's ear: "A second plane hit the second tower. America is under attack."
Bush stayed in the classroom another five minutes or so, listening to children read. He later said he was trying to project calm.
http://story.news.yahoo.com/news?tmpl=story&u=/ap/20040619/ap_on_re_us/sept_11_five_year_plot&cid=519&ncid=716