A fire broke out in the crowded República Cromañón nightclub in Buenos Aires, Argentina on 30 December 2004, killing 194 people and leaving at least 1,492 injured.

República Cromañón (Cro-Magnon Republic) was a venue that held concerts and events, on 3060-3066-3070 Bartolomé Mitre street in the Balvanera neighbourhood of Buenos Aires.

[3] The fire started when a pyrotechnic flare, a popular device in New Year's Eve celebrations, was set off and ignited foam in the ceiling.

The fireworks accident quickly spread as the materials used in the building for decoration were flammable: mostly wood, styrofoam, acoustic panels and a shade sail made of polyester fibre.

[5] After the fire the technical institution INTI found that, due to the materials and volume of the building, the concentration of cyanide in the air would have been about 225 ppm, sufficient to cause death within minutes of inhalation.

In addition to the city's poor planning for a disaster of this magnitude, critics pointed to Ibarra for failing to reorganize Buenos Aires' inspection system.

Relatives and friends of the dead organized several marches to Plaza de Mayo[9] demanding the resignation of Aníbal Ibarra as Head of Government of Buenos Aires, the conviction of Omar Chabán, and a more efficient inspection system.

On 14 November 2005, an impeachment jury formed by the Buenos Aires Legislature suspended Ibarra for four months, pending an investigation of his performance that could lead to his removal.