República Cromañón was a concert venue on Bartolomé Mitre street in Balvanera, run by the entertainment promoter Omar Chabán. On the night of 30 December 2004 the band Callejeros was playing - the same band that had opened the club eight months earlier. The hall was packed far beyond what it should have held. Somewhere in the crowd, a fan lit a pyrotechnic flare, the kind sold cheaply for New Year's celebrations across Argentina. Both Chabán and the band's singer had warned the audience not to set off flares indoors. Someone did anyway. The flare struck a shade sail of polyester netting strung beneath the ceiling, and the netting caught.

The fire would have been survivable in a safer building. This was not a safer building. The ceiling materials were flammable - wood, styrofoam, acoustic panels, polyester - and in places the insulation was nothing more than teddy-bear stuffing used as a cheap substitute for proper wool fiber. The netting melted as it burned and fell on the crowd as a rain of fire. Worse than the flames was the smoke: investigators later found the toxic air would have reached cyanide concentrations high enough to kill within minutes, a poison one expert compared to a gas chamber. And there was almost nowhere to run. Of the six front doors, four were locked. One emergency exit was chained shut; another was blocked by a fence in front of the stage. Of fifteen fire extinguishers, ten were empty and useless. The club's fire-safety license had expired the month before. People died not because they could not move fast enough, but because the doors that should have saved them had been sealed against them.

It is easy to let a figure like 194 stay a figure. The reality was a generation of a neighborhood gone in a single night. Rescuers pulling people from the smoke found teenagers and young adults, and then, devastatingly, they found children and babies from the room their parents had used as a nursery so they could watch the show. In the days that followed, families walked through morgues to identify sons and daughters. President Néstor Kirchner declared three days of national mourning. Across the city, nightclubs went dark. Pope John Paul II sent his condolences to the grieving. But for the mothers and fathers and the survivors who carried burns and grief out of that hall, no decree could answer the question of why the exits had been locked at all.

The grief turned into a demand for accountability that reshaped Argentine public life. Investigators found that Cromañón had been overdue for inspection since November and that the city's entire safety-inspection system was broken. The mayor of Buenos Aires, Aníbal Ibarra, was ultimately removed from office through impeachment over the failures. Omar Chabán was sentenced to twenty years in prison; after appeals, members of the band were convicted as well, and in all some eighteen people were jailed. Argentina rebuilt its nightlife safety culture from the ground up. Today, 194 trees stand planted in memory of the dead, and the families who survived - organized under the cry 'Que No Se Repita,' that it never happen again - keep their children's names alive. Two decades on, Buenos Aires still gathers each 30 December to remember a night when the music stopped and the doors would not open.