I lived in Waco during the event. I was in high school at the time and I personally witnessed the fire that burned the compound down. (A friend and I were skipping school, heard it on the radio, and we drove out to Elk and saw the huge plume of smoke).
Basically they were a bunch of religious nutcases with an apocalyptic bent. The Branch Davidian sect had been in Waco since the early days. They had a church compound actually located in the city of Waco for some time. That compound is now an (unrelated) exclusive prep school, which ironically was the school my above mentioned friend attended. The church broke up in the 1960’s after the end of the world didn’t happen or something; one branch went sort of mainstream Seventh Day Adventist, and the hardcore apocalypticos went out of town to a new compound, which eventually was taken over by Vernon Howe, aka David Koresh.
They had run-ins with local law enforcement, and problems with their neighbors mainly regarding all the firearm use. Remember this is rural Texas where heavy firearm use is de rigueur, so the fact that neighbors were constantly calling the sheriff was meaningful. Anyway, the feds investigated, including sending in undercover agents posing as converts, and keeping the compound under constant surveillance from a rented farmhouse. They were right to ask for warrants, and the judges were right in granting them. These people were breaking the law and were an immediate danger to the community. Not to mention all the child abuse that was happening there.
The real problem was the way the ATF screwed up the raid. The local media was tipped off early that a raid was coming. The Waco Tribune Herald ran a front page multi-day series on the sect just a week before the raid. On the day of the raid the news media was at the compound before the ATF arrived. It was clear that the sect knew the raid was coming. The sect knew, the ATF knew, and they both knew that the others knew. The ATF decided to just go ahead and have an all out gun battle. Bad decision. The sect was indeed heavily armed, well fortified, and well trained. Another criticism is that the raid occurred on a Sunday morning. Most of the cult members worked at regular jobs, and Koresh himself would travel to Waco on weekdays to evangelize; his right hand man was a lawyer who worked in town. Why the ATF didn’t just wait until Monday and pick up the cult leadership at their workplaces proves to some that the feds wanted a gun battle. Anyway. The ATF botched the raid and then had to deal with a two month long siege that could only end badly.
About half the children were released halfway through the siege. After Koresh backtracked on several deals to give up the feds had no other choice but to try and force them out. The cult members would rather die. As a tank poked holes in the compound walls to insert tear gas, some cult members set the compound on fire, shot and killed many of their own members, including children, then shot themselves. That’s about it.
It is one of those events that conspiratorialists love, and the internet is especially full of misinformation and flat out lies. I scanned the Wikipedia article and found so much misinformation I would have to write an entire essay refuting it. Just the part about how the cult members were loved by their neighbors and the local sheriff is flat out ridiculous. Everyone hated them and all their neighbors feared them. Local law enforcement was overwhelmed with dealing with them.
I hope my viewpoint can help. Frankly, like most people from Waco, I’m just tired of it, and I’ve learned that most media, especially internet media, is completely untrustworthy on this event. If you ask any Wacoan about it you’ll get a similar response, right after they tell you (truthfully) that the compound was not in Waco, not even in the same county.