WELCOME TO GODDARD'S ROLLER COASTER...
The evidence that a bomb went off in the concrete room is solid, and I believe the physical evidence proves that a bomb went off in the concrete room. There is additionally this interesting article: http://spotlight.org/Sept_26/Rangers/rangers.html
However, the following facts I just learned make me feel it's probably impossible to prove that the source of that bomb was not the Davidians. Records of purchases made by the Davidians from gun dealer Henry McMahon prove that during 1992 the Davidians acquired these explosives and explosives materials:
That's a lot of explosive power and ingredients for such power! The Davidians also did business with other gun dealers. I'd be willing to bet that they stored those explosives in the concrete room, which would be wise (assuming it's not filled with women and children). Now, if there is reason to believe that there's that kind of explosive power in a house, and a massive explosion occurs in that house, the most probable explanation is NOT that someone else entered the house and planted a bomb.
The list of purchased explosives above was raised in court and not contested by the Davidians nor their lawyers. The only issue raised in response was that it was legal to purchase those items. While I was recently informed that they had some black powder, but I did not realize how much.
I've been told that the explosive agents above are not high explosives. However, according to one explosives resource, 4 onces of a 2-to-1 mixture of an oxidizer like Potassium Nitrate and Aluminum Powder is equal to one stick of dynamite. Therefore, just those two agents in the list above have power of at least 182 sticks of dynamite! In a closed space, that might do some serious damage; and throw in 50 pounds of black powder to boot... KaBoom! This assumes of course that they were mixed properly, but I really doubt that those explosives ingredients were purchased along with a pound of Igniter cord not to be mixed.
THE DOWNWARD-BENT REBAR
As I noted, melted glass was found inside the room. This made me wonder if the downward-bent rebar may have been a result of it starting to melt. I was informed that the melting point of steel is 2800 degrees. I also found that the "glass transition temperature" is 932 degrees, in both cases, in Fahrenheit. So the glass could melt and the steel not melt. However, I've just learned that the temperatures inside the room reached above 2000 degrees, so it's possible that the rebar started to melt and in so doing began to sag downward. I've seen video of the room after the house was gone and fire was blazing out of the top part of the doorway, so it was probably also blazing out of the hole. I wonder what was burning so fiercely?
It's also possible that the sudden explosion of a large cache of explosives inside the room would blow the hole that we see through the roof, and it's very plausible that it would distribute the debris on the inside as we've seen. Or explosives stored in the room above the concrete room could account for the damage seen. So it seems to me that the evidence pointing to a bomb is most probably linked to the probably unintentional ignition of explosives that the Davidians had.
It's also been suggested that the hole in the roof was caused by a military shaped charge, but I can't find any evidence of the existence of shaped charges that would not also take out rebar.
Well, I stand behind my initial proof that a bomb exploded and demolished the interior of the room, and I think it was proper to raise this issue and speculate (as I did) that the government -- i.e., the people who were shooting at and thus trying to kill those inside -- did it. If a dozen people are shooting at people in a house, and then a bomb goes off in that house, and it's admitted that some of those people went into the house, on its face, it stands to reason that those attempting to murder those in the house did it. However, I now strongly suspect the Davidian's stored a large cache of explosives that was exploded by the fire.
Since the purpose of my Waco-Bomb page was to make a plausible case against the government, and since I don't feel there is a plausible case in this case regarding the bomb, the purpose of the page has technically expired; but I'll leave the evidentiary photographs up. If someone can convince me that the explosion cannot have been caused by the Davidian's own explosives stockpile, then I'll put the page back up.