Yep, what's said here is absolutely correct.
The bomb, known as the "Tybee Bomb" was a Mk15, Mod 0 bomb (serial number 47782) roughly 11 and a half feet long and three feet wide. The 7,600 pound device was dropped from an altitude of 7,200 feet at a ground speed of 194 knots... Into the Atlantic Ocean near the mouth of the Wassaw Sound, just south of Tybee Island, GA. The location is just a few miles from Savannah, GA.
Aboard the bomb was approximately 1,200 pounds of Uranium 238, about 400 pounds of conventional TNT-type explosives, the grapefruit-sized "pit" made almost entirely of plutonium (some say it had a tridium core), and it's electronics and batteries. Almost the entire bomb was made of nonferrous metals, including what's already been mentioned and aircraft-grade aluminum.
As local residents, our biggest fear isn't spontaneous nuclear explosion - that's very unlikely. Our biggest fear is that an enemy of the US will find it before we do (it WILL, after all, be found - these things are good for tens of thousands of years) and purposely set it off (it could simply be made to function again, right where it is, charged with batteries, and... BOOM) in a terrorist strike. The 1.5 megaton yield of this bomb would literally either atomize, incinerate, blast, or poison an area in the Southeastern US from Jacksonville, Florida to Atlanta, Georgia to Charleston, South Carolina. Savannah, Hilton Head and surrounding communities would likely be vaporized or at least completely incinerated.
The show says that "about a quarter of a million people would die." This is a very gross understatement - there are more than 1.4 million people living in Savannah alone! The death toll would probably approach 4 to 5 million (some in Jax, Atlanta and Charleston would also die, after all), with many more to die later from radiation sickness and cancer-related illnesses.
Second to the fear of terrorism would be the fear that the materials within the bomb could leech out into either the estuary (which is a very productive fishery and shrimpery and would likely poison people nationwide) or down into the aquifer, which supplies most of the Southeastern US with water. Interestingly, the aquifer is the Floridian Aquifer, meaning that the waters affected are those that supply Atlanta, Miami, Jacksonville, Savannah and more... Including Florida's springs like Ginnie, Vortex, and Rainbow. While this may seem a distant threat, keep in mind that there is only about 40 feet of sediment seperating the sea from the aquifer... And the theory is that the Bomb is likely lodged in the middle of that.
Interestingly, if this is true, and if the Bomb's CONVENTIONAL explosives were to detonate (the bomb went off, but didn't "go nuclear") then aside from throwing unspent radioactive debris everywhere, it would probably blow a hole in the Floridian Aquifer, beneath the seabed... Which would allow the aquifer to be quite contaminated with seawater.
With these two main concerns in mind, it astounds me when I hear the Federal government claim, "It's nothing but a big paperweight - it CAN'T go nuclear. It is not a threat. It is not hurting anybody sitting where it sits." Even sillier is the idea that we shouldn't bother looking for it because if we do find it, we don't want to move it as it would pose a bigger threat to move it than leave it where it sits.
The reality is... We have no idea if it poses a threat where it sits or not. THAT is the REASON that the device needs to be found - so that we can assess the threat. Even if, after finding it, it's decided to leave an explosive (even if the nuke portion of it is ignored) sitting halfway between seawater and the Floridian Aquifer (I can't imagine that would be the case) it should AT LEAST be guarded so that it can not be tampered with, armed and set off.
I can assure these government officials that if this thing was sitting in THEIR backyard, they'd be more concerned about it.
Given that they aren't looking for it... Given that they don't seem to care... Given that they have twice declared it "irretreivably lost," I'll look for it.
And guess what... When I find it, what I do with it is my business.

Should be worth many billions of dollars on the black market...
