Waco.

From From My Cold Dead Fingers: Why America Needs Guns by Sheriff Richard I. Mack:

Attorney General Janet Reno ordered the final assault, knowing at least 25 children were still inside. On April 19, 1993, CEV tanks began pounding holes in the walls and structures at Mount Carmel Center, pumping in CS gas. While armored combat vehicles rammed and rocked entire buildings, spitting nauseating tear gas into rooms containing babies, FBI agent Byron Sage shouted over loudspeakers, "This is not an assault! Do not shoot. We are not entering your compound." Ambulances and local hospitals had been put on alert, and agents continued to call out, "You are responsible for your own actions. Come out now and you will not be harmed." Sheila Martin's husband Wayne called 911 and pleaded, "Call them off -- there are women and children in here!" When the Davidians began firing in self-defense at the building-crunching tanks, federal agents became indiscriminate in spewing clouds of tear gas anywhere they could, irrespective of where women and children might have gathered for safety. Many had gone to a second-story location from which there was no exit.

The Compound exploded and all but nine inside perished.