In 1993, ATF approached the Waco compound, starting a stand off that lasted more than a month.
By 1993, David Koresh led the Branch Davidians. They lived in the Waco compound. Koresh taught about an imminent second coming, with many disasters. For this reason, the group started stockpiling food, water, and weapons. The ATF heard that the group would change semi-automatic weapons to automatic weapons without a permit. They decided to investigate.
On February 28, 1993, about a 100 law enforcement descended on the compound. They had warrants to arrest David Koresh and search the property. As they approached the Waco compound, someone fired a weapon. No one knows which started it. The gunfire fight lasted about 45 minutes and left dead on both sides. At this point ATF withdrew, called in the FBI and started a standoff that would last 51 days. The standoff would end with over 70 people dead.