In 1993 there was a community located outside of Waco, Texas of Branch Davidian believers. Their compound was known as Mt. Carmel. The leader of the group was David Koresh.
David Koresh was accused of misconduct and sexual abuse. The group was suspected of stockpiling illegal weapons. ATF authorities got a search warrant to find the weapons. It turns out that the Branch Davidians were legally purchasing many weapons, but the ATF used the excuse that some of the parts they were purchasing could potentially be used to modify weapons illegally.
A professional advised them against arrested Koresh at the compound, saying that because of the brainwashing his followers were likely to respond violently.
When the ATF began investigating the gun issue, Koresh invited them to come inspect the compound and guns and paperwork- but they declined.
So based on what is most likely a combination of prejudice, lies, speculation and repression the ATF raided the WACO compound on February 28th, 1993. The Davidians were tipped off about the raid, and despite knowing this the ATF continued with it. Koresh came out to meet the ATF when they arrived, unarmed. At that point, shots were fired. It is still disputed as to which party fired the first shots.
Over the next 2 hours a gun battle ensued. 4 ATF agents were killed, and 16 more were injured. 5 Davidians were killed- 2 by friendly fire.
For 51 days a seige/standoff ensued. THe FBI cut off Davidian communications with anyone but the FBI.
On April 19, 1993 the FBI began their final raid on the compound. They used heavy artillery, tear gas, armored vehicles, and grenades. At the end the compound caught on fire. 76 people died- 20 of whom were children.