The US Army Center of Military History’s website in memory of the 9-11 attack on the Pentagon.
http://www.history.army.mil/news/2016/160900a_911.html
The book “Then Came the Fire” came out for the 10th Anniversary and has some of the 900 interviews done with survivors and rescue personnel at the Pentagon.
“Then Came The Fire” pdf »
I know a couple of guys who crawled through the burning Pentagon to safety.