I know an explosives physicist working for the govt. BTW, this is not some arm-chair wannabe that blew something up once 30 years ago, this guy is a physicist who works in weapons development and who does computer blast simulation modeling and then blows stuff up on a regular basis to prove the predictions. When asked whether it was possible for the truck bomb to do the damage it did, the answer was a qualified yes. Without going into details, suffice it to say that it would have required several people working with military precision to obtain the necessary optimimal conditions that would result in the damage experienced at the Murrah Bldg. So while it was possible for that truck bomb to do the damage it supposedly did, it would have required more than one person.
If this rules out the conspiracy theorists who claim there were additional charges inside the building, it also begs the question, who where the other people responsible for making the truck bomb work?
Your question is one I asked? The other people were Al Qaeda explosives experts based in the Philippines (Abu Sayyaf, Ramzi Yousef, Hakim Murad...etc..) I detail this in Chapter 16: The Farmer Meets the Terrorist.