
Abaddon and Apollyon
Saddam Hussein has many underground bunkers. It is said that some are so deep and so well built that they are virtually impervious to destruction. In our current arsenal, we have the Guided Bomb Unit-28 (GBU-28) BLU-113 Penetrator.

It's stated purpose is "for penetrating hardened Iraqi command centers located deep underground. The GBU-28 is a 5,000 pound laser-guided conventional munition that uses a 4,400-pound penetrating warhead. It is capable of penetrating more than 20 feet of reinforced concrete and deeper than 100 feet underground. http://www.military.com/resources/eqg/eqgmain?file=gbu28&cat=o&lev=2
We also have the 15,000-pound Daisy Cutter bomb.

The United States has used 15,000-pound ``daisy cutter'' bombs, similar to the one shown in this undated file photo, in the Afghanistan campaign, a defense official said Monday Nov. 5, 2001. The BLU-82 bomb, was developed to provide the USAF with a high-blast bomb for creating corridors through large minefields, but also for use against ground forces. This bomb was also used to clear helicopter landing areas in the jungle. The bomb was designed to be delivered by pushing it out of the rear cargo doors of the USAF's MC-130H Combat Talon (Hercules) aircraft. The bomb was first used in the mine-clearing role by the USAF in 1991, to open the Desert Storm ground war. ( AP Photo/JANES
http://www.commondreams.org/headlines01/1106-02.htm
But then again, there is our newer 21,000-pound MOAB, short for "massive ordnance air burst" bomb. MOAB's massive explosive punch is similar to a small nuclear weapon. http://www.abcnews.go.com/sections/wnt/world/newbomb030225.html

Commonly called "bunker busters", these are appropriate fits for John's Abaddon and Apollyon which means "destroyer" for "bust" and "destroy" are synonymous terms.
Now word is coming out about "Big Blue", a 30,000 pound "cousin" of MOAB that's designed to penetrate the earth and blow up deep bunkers.
http://www.globalsecurity.org/org/news/2003/030313-palace-buster01.htm
Supposedly it doesn't exist yet, but it's noted that there are many weapons that "don't exist" actually do exist. Additionally, GlobalSecurity.org reports further:
Although the Direct Strike Hard Target Weapon concept was unfunded as of 1997, in early 2002 it was reported that Northrop-Grumman and Lockheed Martin were working on a 30,000-lb. earth penetrating guided conventional weapon, said to be known as "Big BLU" or "Big Blue" [which is also the nickname of the 15,000-lb surface burst BLU-82]. Big BLU will be GPS guided and feature cobalt-alloy penetrator bomb body that enables it to penetrate to depths of up to 100 feet below the surface before detonating. The bombs are so large that a bomber such as the B-2 could carry one of them. As of March 2002 reportedly three Big BLUs had been ordered by the Air Force on an urgent basis ["Inside The Ring," By Bill Gertz and Rowan Scarborough, Washington Times March 15, 2002 Pg. 10].
