Sounds good... getting there.
Still a picture is worth a thousand words.
Ever play the block game when you were 3 years old? This fits in here... this doesn't fit in here.
Try this one also: Why would you put gravel and sand over grass that wasn't affected?
The gravel was because of the threat of rain coming and the need to continually move heavy equipment. The road was constructed to facilitate rapid movements of the cranes, dump trucks, fuel vehicles, fire engines, material delivery vehicles etc., as well as all the supporting trailers and vehicles brought in by the local agencies. The thought was if the ground got soft because of rain (and I believe rain was forcasted for Wednesday that week), the vehicles, and thus the rescue and recovery operations, would be halted. That would have been unacceptable to the American public. The photo of the plane superimposed on the building is way out of scale, that's one reason why it doesn't fit.
Let's see if some of the picture I post clarify some of the linguring questions.