TIL that On September 10, 2001, U.S. Defense Secretary Donald Rumsfeld said in a press conference that $2.3 trillion from Pentagon had gone missing, but the 9/11 attacks took attention away from this news, so it was forgotten.

https://en.wikipedia.org/wiki/United_States_Department_of_Defense

https://www.reddit.com/r/todayilearned/comments/1662yei/til_that_on_september_10_2001_us_defense/