Lack of evidence and setting precedent.

On Sepember 11th 2001 4 airliners were allegedly used as missiles in 3 terrorist attacks and one failed terrorist attack. These airliners, to my knowledge, were never identified by serial number. This sets precedent, if I am not mistaken.

Secondly, the lack of physical evidence is one of the most quoted aspects in debate, where the 'truthers' quote lack of evidence frequently and the rebutal usually points to a small amount (in terms of mass) of evidence that certainly implies airliners.

This would imply that precedent in airliner collisions had been set 8 seperate times in one day. Well technically the precedent was only set once for each instance and then chronlogicaly the following events had not. For each instance (lack of SN and lack of mass) to never happen and then all come into play on the same day is a mathematical improbability that approaches impossibility.

The problem is that it is impossible to prove a negative, unless of course it is wrong (and therefore not a negative). In other words, we cant prove something didnt happen. So, my question to everyone here is:

Can you disprove the precedents set on 911? Can you find other instances where anything happened to an airliner where over 95% of the mass was destroyed on impact, or where not one serial number was found? Alternatively can you find any piece of 911 evidence from any of the 4 planes that states serial numbers?

The evidence might be locked away.

Plane parts at the crash site may not fit the airliner.

TV coverage said explosion, no plane was sighted.

Pentagon site cameras may have more evidence.

Government and Airline oddities on that day seem too coincidental.