7.4 magnitude earthquake rocks Mexico, but no major damage reported

MEXICO CITY — A powerful and prolonged earthquake rocked Mexico on Tuesday, toppling houses near the epicenter in the south, cracking building facades in this sprawling capital and briefly terrifying a population well-schooled in natural disasters.

Despite the quake’s 7.4 magnitude, however, there were no reports of serious injury or major damage, according to President Felipe Calderon and officials across the country. Aftershocks rattled the area through the rest of the day.

“This is one of the strongest we’ve ever felt,” Calderon said, urging Mexicans to remain calm.

In this capital of 20 million people, the quake shook office buildings and apartment houses and sent hundreds of thousands of people into the streets seeking safety. A pedestrian bridge on the outskirts of the city was wrenched from its girders and crushed a passenger bus below. The bus was empty, save for the driver, who escaped with minor injuries.

The southern Guerrero and Oaxaca states, along whose shared border the epicenter of the quake was pinpointed 12 miles below the surface, apparently took the brunt. Guerrero Gov. Angel Aguirre said more than 500 small homes in two remote rural villages were damaged, and at least 60 of those collapsed.

Oaxaca Gov. Gabino Cue reported cracks and broken windows in several schools and minor damage to a number of Oaxaca City’s iconic monuments and colonial-era buildings. He said signposts had fallen in the city, and the quake had triggered small landslides on a handful of rural roads.

The third floor of a university being remodeled collapsed, he added. Five people were injured in these incidents, none of them seriously, authorities said.

U.S. President Barack Obama’s older daughter, Malia, was vacationing in Oaxaca with school friends but was not hurt, White House officials said. Malia, 13, “is safe and was never in danger,” said Michelle Obama’s spokeswoman, Kristina Schake.

In Mexico City, Tuesday’s shaking revived memories of the devastating 1985 quake that destroyed parts of the capital and killed more than 10,000 people. Because of that and other natural disasters, residents here periodically rehearse evacuations and emergency procedures.

That practice was on full view Tuesday. Although there were, as Calderon put it, scattered “scenes of panic,” many of the evacuations were orderly. Workers, from executives in business suits to the aproned cleaning staff, filed from offices, down stairs and into the streets, where they gathered at pre-designated spots. Pre-assigned marshals donned rescue vests and made sure everyone was accounted for. Evacuation alarms screeched in the background.

Hours later, many had not returned to their buildings. Officials from the federal attorney general’s office were working in a nearby Starbucks.

Mexico City Mayor Marcelo Ebrard, who within minutes of the temblor took to the skies in a helicopter to survey the city, said the toll seemed limited to cracked walls, loosened plaster and tilting buildings. Telephone service and electricity to more than 2 million customers were interrupted for several hours; traffic lights went blank, and one hospital said it would close because of damage and transfer patients to another facility.

The federal Chamber of Deputies, the lower house of Congress, was in the middle of a legislative debate when members were told to clear the building. An elaborate, enormous crystal chandelier swayed precariously back and forth above the chamber, casting an odd light over the scurrying legislators.

The quake hit at 12:02 Mexico City time. There was an initial rocking, a pause and then a much stronger, sustained bouncing motion.

Initially, the U.S. Geological Survey measured the quake at a magnitude 7.6, then revised its reading to 7.4. The epicenter was about 115 miles east of the tourist resort of Acapulco, in Guerrero, and 100 miles west of Oaxaca City.