A Mexican prison riot in which 44 people were stabbed, strangled or beaten to death was originally mourned as another Latin American prison tragedy, just days after a fire in a Honduras jail killed more than 350 inmates.
Yet investigations now reveal that the violence was a cover for the escape of 30 members of the Zetas drug cartel, blamed for some of Mexico's most brutal killings.
The 44 who died were members of the rival Gulf cartel.
The Apodaca complex in the northern Mexican state of Nuevo Leon saw one of the country's worst episodes of prison violence on Sunday. Prison guards, officials and the director of the jail have been sacked, accused of colluding with the gang members.
"The treachery, corruption and complicity of some can spoil the work and service of good policemen, soldiers and marines who risk their lives every day for our security," Nuevo Leon Governor Rodrigo Medina told Reuters.
The escapees are being sought by authorities who are offering just under a million dollars as a reward for any information. "The Mexican prison system has collapsed," Raul Benitez, a professor at Mexico's National Autonomous University (UNAM) told AP. "The prisons in some states are controlled by organized crime."
Like many of Latin America's jails, those in Mexico are severely overcrowded. The country's jails were build for around 185,000 and hold around 45,000 more, according to the government. More than 400 inmates have been kiled since the beginning of 2009, according to the country's Human Rights Commission.
On Monday, Spanish-language service BBC Mundo posted footage of a mob of angry families of the dead inmates trying to force their way into the prison.
Mexico's drug wars have killed some 47,000 people since President Felipe Calderón took office in December 2006. His National Action Party (PAN) is unlikely to win July's presidential election in the wake of the drug war, paving the way for the Institutional Revolutionary Party (PRI) to take back power.