We Americans love a challenge.
Karl Bernd Esser, the German architect who says he designed the bunker buried deep underneath the palace complex, recently told Germany's ZDF television that the walls were three meters (10 feet) thick and could withstand temperatures up to 300 degrees Celsius and survive anything short of a direct hit from a nuclear weapon the size of that which destroyed Hiroshima in 1945.
Sounds like a testable theory.
Two underground passages lead directly to the Tigris.
Delta Force, please pick up on the red phone...
I bet they aren't all that hardened. A flood is good, too.