' In altering the structure of the intelligence community, it is essential to deliberate long and hard - and not to be stampeded into doing harm....Reform may now be necessary.

CENTERFORSECURITYPOLICY: 'First, do no harm'

But the experts suggested that the very structure of the U.S. intelligence system may have to be looked at, especially because of the case that seems to be developing as the massive investigation into Tuesday's attacks continues.

CNN: Experts: A variety of intelligence factors may have played a role

Throughout its fifty-plus year history, the PIAB has had immense and long-lasting impact on the structure, management, and operations of US intelligence.

WHITEHOUSE: History