Earlier, I missed this paragraph in the LA Times article linked below:
Among the flying public grounded
that day were the president's
parents, who found themselves
stranded in Wisconsin. Bush was
able to reach his father, as well as
First Lady Laura Bush, who was
in Washington. But as he
discussed his personal reactions,
Bush also wanted there to be no
doubt about his focus on the task
at hand.
Poppy was at the White House that day, NOT in Wisconsin. (Thanks to Jerky for the catch)
Tim Russert, on NBC's Today Show, 9-13-11:
"Ironically, former President Bush was in the White House on Tuesday morning when this attack occurred. He happened to be visiting there in town. He did not go to the situation room and become part of the negotiations or discussions, but he... left the White House. But he is someone that the current president loves and respects, and those are two pretty good qualities to have in any adviser. During the situation when our plane was forced to land in China, former President Bush was an invaluable adviser. And I would think that this president will utilize his knowledge, and his thoughts, and his experiences, and I think most Americans would understand that; in fact, encourage it" (NBC's "Today," Sept. 13).
Update: Okay, mystery maybe solved... from the 9-14-01 NY Daily News:
The former President spent Monday night at the White House but left early Tuesday. He was in the air, en route to a speech in St. Paul, when terrorists attacked New
York and Washington. The ex-President was diverted to Milwaukee, where he spent Tuesday night.