Firefighters belonging to the Tacubaya sector and workers dig for survivors after an explosion at an adjacent building to the executive tower of Mexico's state-owned oil company PEMEX, in Mexico City, Thursday Jan. 31, 2013. A large explosion occurred in the lower floors of the building.

An injured person is transported on a stretcher the headquarters of state oil giant Pemex in Mexico City Jan. 31.

Rescue workers head for the skyscraper.

A helicopter overflies the area following a blast inside the skyscraper that houses the headquarters of state-owned Mexican oil giant Pemex.

A dog equipped with a dog wheelchair stands next to a metal pail at the "Milagros Caninos," sanctuary for abused and abandoned dogs, in Mexico City, Jan. 11. About 128 abused dogs are sheltered at the Milagros Caninos sanctuary. Dogs on wheelchairs, blind, deaf or ill frolic and run around the huge sanctuary in the southern part of Mexico City.

Patricia Ruiz plays with dogs at her sanctuary for abused and abandoned dogs.

Pilgrims wait their turn to enter the Basilica of Guadalupe, in Mexico City, on Dec. 12. Hundreds of thousands of people from all over the country converge on Mexico's holy Roman Catholic site, many bringing with them images or statues of Mexico's patron saint to be blessed, marking the Virgin's Dec. 12 feast day.

Hundreds of pilgrims arrive to the Basilica de Guadalupe in Mexico City on Dec. 12. Mexicans celebrated the appearance of the Virgin of Guadalupe to Juan Diego in 1531.

A pilgrim holds an image of the Guadalupe Virgin at the Basilica de Guadalupe in Mexico City on Dec. 12. Mexicans celebrated the appearance of the Virgin of Guadalupe to Juan Diego in 1531.

People carrying images of the Virgin of Guadalujpe look up at the original image of her inside the Basilica of Guadalupe in Mexico City.

Fifteen-year-old girls pose for a group picture at the Franz Mayer museum before a mass Quinceanera birthday celebration in Mexico City, April 28.

Fifteen-year-old girls take pictures of themselves during a mass Quinceanera.

Girls dressed in evening gowns laugh inside a bus.

A 15-year-old girl shouts from the inside a bus during a mass Quinceanera.

Cecilia, center, plays with her dress.

A 15-year-old girl gets ready for a mass Quinceanera birthday celebration.

Girls dressed in evening gowns pose for photographs at Zocalo square in Mexico City.

A segment of Mexican artist Rivelino's new installation, "Raices" or "Roots" reaches to the top of the Corpus Christi ex-convent in Mexico City.

Volunteers ascend the steps of Tlatelolco Plaza of the Three Cultures carrying a segment of Mexican artist Rivelino's new installation, "Raices" or "Roots, in Mexico City.

Rubbish is piled up in between parked cars in downtown Mexico City, Dec. 26. After city authorities shut down the Bordo Poniente landfill, one of the largest dumps in the world, garbage has started to accumulate and trucks have been slower to pick it up, according to local media.

A woman covers her face as she walks past piled up garbage that accumulated over the Christmas weekend in front of the Monument to Benito Juarez, one of Mexico's most important statesmen, in downtown Mexico City, Dec. 26. Garbage disposal workers complain that since last week's official closing of the Bordo Poniente city dump,one of the world's largest, they are backed up trying to get rid of the garbage.

Rubbish is piled up next to the monument of Mexico's late President Benito Juarez in Mexico City, Dec. 26.

Mexican children eat portions of a 50-metre-long "Taco" (Mexican typical food) at Garibaldi square in Mexico City, on Sept. 22.