Mexican search and rescue teams worked through the night after an earthquake rocked one of the world’s largest urban centers, killing hundreds and reducing buildings to rubble.

Military police, paramedics and volunteers, aided by giant flood lights, sifted through the rubble to locate survivors, often calling for silence to listen for voices of trapped victims. The 7.2 magnitude quake ravaged the area of more than 20 million people, killing at least 217 people and leaving an unknown number of others still unaccounted for.

At least 86 people were killed in Mexico City, 71 in Morelos, and 43 in Puebla, according to the latest figures from National Civil Protection Coordinator Luis Felipe Puente.

At a collapsed six-story office building in the Condesa neighborhood, hundreds of people rushed to bring bottled water, food, batteries and flashlights to rescue crews while bulldozers and other earth-moving equipment removed debris.

Quake Anniversary

Tuesday’s quake struck 32 years to the day after a temblor with an 8.0 magnitude killed 5,000 people — and hours after annual safety drills were held on the anniversary. The disaster temporarily closed the airport, stopped the metro and ended trading on the Mexican Stock Exchange. The exchange planned to open as normal Wednesday.

In Mexico City, smoke plumes rose near the financial thoroughfare of Paseo de La Reforma, which was flooded with people — many wearing hard hats — as buildings swayed. Fallen concrete and shattered glass littered the streets.

At the Instituto Renacimiento, a crenelated Catholic school, a massive turret had plummeted to earth, ripping apart a wrought-iron fence and destroying a Porsche. Alarms didn’t ring until after the ground stopped shaking, but all the children were evacuated safely, said Javier Osorio, a rescue worker.

Intravenous Drips

At the nearby Hospital Obregon, about 45 patients were taken outdoors, some with babies and some attached to intravenous drips. Workers tied sheets to trees to shade them.

At least 27 buildings in Mexico City collapsed, President Enrique Pena Nieto told Televisa news. He was returning to the capital from Oaxaca to take charge of the crisis, but couldn’t land in the city due to damage, according to Televisa news. He was to survey the city from the air, hold a coordination meeting and address the nation in the evening.

“The priority is to help victims that have been affected, and rescue those that are trapped in buildings,” he said.

Worried that the quake could add to the economy’s woes, investors sold Mexican assets on Tuesday, with the iShares MSCI Mexico Capped ETF dropping 0.5 percent. The Mexican peso fell 0.2 percent on Tuesday, although it recovered from that loss with a 0.4 percent advance in Wednesday’s session to reach 17.7355 per dollar in London morning trading.

Power Outages

Power had been restored to 70 percent of affected areas after the quake had earlier cut supply to over 4.7 million people in five states and Mexico City, the Federal Electricity Commission said. Pemex, the state oil company, said it had activated its security protocol.

Mexico is one of the world’s most quake-prone nations, sitting at the intersection of four major crustal plates, according to the U.S. Geological Survey.

“This is a highly active zone of seismicity, so it’s not something that’s unusual for this region,” said Julie Dutton, a geophysicist at the agency.

The epicenter of Tuesday’s temblor was in Puebla, about 115 kilometers (71 miles) southeast of the capital, Dutton said. On Sept. 7, a temblor hit offshore near Chiapas state with a magnitude of 8.2, according to the Geological Survey and Mexico’s National Seismological Service. Tuesday’s quake was much nearer to the capital.

Luther Beatriz Ramirez, a government employee, said she was working when her building began to shake. She ran, leaving behind her keys and wallet in an office suddenly littered with ceiling tiles and dirt.

“This was so much worse than the one a few weeks ago,” Ramirez said.