Only the Official 9/11 Story is allowed
If you were correct and engineers, physicists, materials scientists, etc. had been allowed to examine the wreckage at length, take samples, and do independent studies, as is normal after such disasters, there would be far fewer 9/11 conspiracy theories.
As it is, the US government severely restricted access, then started hauling away and destroying the forensic evidence within a very short amount of time, as well as silencing witnesses, erasing footage, deleting early news reports, etc.
The official report from NIST (National Institute of Standards and Technology) has huge mathematical and factual errors (as in how the buildings were built). When confronted with these errors, and in particular how no independent corroboration of the official collapse scenario is possible, the US government has said, “We can’t show you our evidence because of national security issues.” Does that sound familiar?
Architects and Engineers for 9/11 Truth (I’m a member) has been fighting and slowly winning the battle to get the real story behind what caused the collapse of three buildings with two planes. I certainly don’t claim to know what happened, but I’m 100% sure that the official story is wrong.