TWA 800 was without doubt brought down by a missile. The only open question is who fired it.
Rogue elements of the Iranian military turned mercenary and hired by a wealthy Iranian family who lost loved ones in the shoot down of Iran Air flight 655 by the US Vincennes.
This is what I have been told by someone in a position to know. I would like to mention the rest of what I was told, and especially the evidence to support it, but the nature of it is such that it can be easily tracked back to it's source.
I hope that the actual truth of this event will get revealed in the next 5-10 years. I can't see how so many people would keep quiet about it for longer than that.