Oaxaca, Mexico - At least 60 people are dead after one of the most powerful earthquakes in Mexico's history struck late Thursday on its southern coast, toppling buildings, destroying hospitals and causing people to flee violently swaying skyscrapers in the capital city hundreds of miles away.

In Juchitan de Zaragoza, a largely indigenous city in a remote corner of Oaxaca state, rescuers spent Friday desperately trying to reach people trapped under the rubble.

"This is the most critical situation in the whole history of the city," Mayor Gloria Sánchez said in a radio interview. At least one hundred homes had collapsed, Mayor Sanchez said, and the city's only hospital was so badly damaged that doctors were treating the wounded in a courtyard.

The U.S. Geological Survey said the earthquake hit about 60 miles off the coast of Chiapas state with a magnitude of 8.1 - slightly stronger than the devastating magnitude 8 quake that killed thousands of people in Mexico City in 1985, scarring a generation.

Fifty million Mexicans felt Thursday night's quake and more than 1.8 million people lost electricity, said Mexican President Enrique Peña Nieto, who said it was the country's biggest earthquake in at least a century.

The President traveled to the region immediately after the quake struck and visited the worst hit areas Friday. By early Saturday the death toll stood at 60. It is expected to rise further in the coming days as bodies are recovered from under collapsed buildings & homes.

By far the most severe damage was in the states of Oaxaca, Tabasco and Chiapas, all near the epicenter, where at least 37 people died and at least 200 people were injured. Schools were closed across 11 states Friday so authorities could check them for safety.

Luis Felipe Puente, head of Mexico's national emergency services agency, said 45 people died in Oaxaca state. 17 of them were killed in Juchitan, home to the indigenous Zapotec people, where the local government headquarters, the city's biggest school and a major church were all reduced to rubble.

Sanchez, the city's mayor, said rescue operations were underway for least three people buried alive, one at the government building and two more at a collapsed hotel. At least 500 people had been displaced, she said, adding that the city was converting sports stadiums into temporary shelters.

Ten people died east of Oaxaca in the state of Chiapas, Puente said. They included two women who died when a house and a wall collapsed in the city of San Cristobal, Chiapas Gov. Manuel Velasco said.

Three people died in the Gulf Coast state of Tabasco. One of them was a child who was killed when a wall collapsed, Gov. Arturo Nunez said. Another was a baby who died in a children's hospital that lost electricity, cutting off the infant's ventilator.

Peña Nieto said 260 aftershocks were felt in Oaxaca and Chiapas on Friday, the most intense registering a magnitude of 6.1.

The earthquake triggered tsunami waves as high as 3.3 feet at the port of Salina Cruz in Oaxaca, according to the U.S. National Weather Service's Pacific Tsunami Warning Center, and the Mexican navy helped evacuate 8,000 people who lived in vulnerable areas along the coast. By Friday morning, fears that the earthquake might result in a destructive tsunami had calmed.