Playing with definitions doesn't answer anything. If you can't tell, I'm not getting overmuch stressed over this particular argument, because it's absolutely ridiculous.
Also, "without leaving much evidence?" You can't fake that **** man. Planes flew into buildings in one of the most populated areas in the world. If you don't recall, there was a massive pile of debris. You go crawling through it for plane parts? I visited ground zero myself several months after 9-11. They were still cleaning the debris up. That's what happens when two giant towers collapse.
Also, "because there was a fire" is a perfectly good reason for destruction of evidence. It was a big ****ing fire. They were two big ****ing buildings. And the planes hit the towers at very high speeds. The planes wouldn't stay in large peices in such a crash. And what the hell are you suggesting by your personal perceived lack of plane debris? That the planes that thousands of people saw in one of the most populated areas of the world DIDN'T EXIST? You can't just say when your facts are wrong it's due to your own ignorance, and then act like that somehow reinforces your argument.
Also, there are sites dedicated to debunking conspiracy theories. But believe me, people spend much more time attempting to rationalize crazy theories than attempting to refute them. Because most of the time people are smart enough to see when this **** is idiotic.
NIST's Investigation of the Sept. 11 World Trade Center Disaster - Frequently Asked Questions
Debunking the 9/11 Myths: Special Report - Popular Mechanics
Loose Change 2nd Edition Viewer Guide