What really happened at Waco?

The FBI tried to do a direct ault to serve a legal warrant, and were just plain out gunned. As the stand-off continued, they tried tear gas, which is a standard tactic, and the whole place caught. Could the gas have started the fire ?? Certainly. Was that the purpose of the gas ?? Nope. And remember, the sect was already preparing for the end of the world, so they thought they had nothing to lose.