In Pictures: The Deadly Earthquake That Just Rattled Mexico City

The new quake appeared to be unrelated to the magnitude 8.1 temblor that hit Sept. 7 off Mexico's southern coast and also was felt strongly in the capital. U.S. Geological Survey seismologist Paul Earle noted the epicenters of the two quakes were 400 miles (650 kilometers) apart and said most aftershocks are within (60 miles) 100 kilometers. PIC: Rescue work being undertaken. (AP).

A powerful earthquake shook central Mexico on Tuesday, collapsing buildings in plumes of dust and killing at least 149 people. Thousands fled into the streets in panic, and many stayed to help rescue those trapped. PIC: First responders work on removing the rubble of a collapsed building looking for survivors trapped underneath. (AP)

Dozens of buildings tumbled into mounds of rubble or were severely damaged in densely populated parts of Mexico City and nearby states. Mayor Miguel Angel Mancera said buildings fell at 44 places in the capital alone as high-rises across the city swayed sickeningly. PIC: Rescuers, firefighters, policemen, soldiers and volunteers remove rubble and debris from a flattened building in search of survivors. AFP PHOTO / YURI CORTEZ

The quake is the deadliest in Mexico since a 1985 quake on the same date killed thousands. It came less than two weeks after another powerful quake caused 90 deaths in the country's south. PIC: Volunteers search a building that collapsed after an earthquake, in the Roma neighborhood of Mexico City. (AP Photo/Eduardo Verdugo)

The quake sent people throughout the city fleeing from homes and offices, and many people remained in the streets for hours, fearful of returning to the structures. Electricity and cellphone service was interrupted in many areas and traffic was snarled as signal lights went dark. PIC: Volunteers search a building that collapsed after an earthquake, in the Roma neighborhood of Mexico City. (AP Photo/Eduardo Verdugo)

The federal government declared a state of disaster in Mexico City, freeing up emergency funds. President Enrique Pena Nieto said he had ordered all hospitals to open their doors to the injured. PIC: Volunteers search a building that collapsed after an earthquake, in the Roma neighborhood of Mexico City. (AP Photo/Eduardo Verdugo)

The U.S. Geological Survey said the magnitude 7.1 quake hit at 1:14 p.m. (2:15 p.m. EDT) and was centered near the Puebla state town of Raboso, about 76 miles (123 kilometers) southeast of Mexico City.

At one site, reporters saw onlookers cheer as a woman was pulled from the rubble. Rescuers immediately called for silence so they could listen for others who might be trapped. PIC: The body of woman hangs crushed by a collapsed building in the neighborhood of Roma Norte, in Mexico City. (AP Photo/Marco Ugarte).

Earlier in the day, workplaces across Mexico City held earthquake readiness drills on the anniversary of the 1985 quake, a magnitude 8.0 shake that killed thousands of people and devastated large parts of the capital. PIC: Rescue workers and volunteers search a building that collapsed after an earthquake in the Roma neighborhood of Mexico City. (AP Photo/Eduardo Verdugo)

Mexico City's international airport suspended operations and was checking facilities for damage. Much of Mexico City is built on former lakebed, and the soil can amplify the effects of earthquakes centered hundreds of miles away. PIC: Rescue workers and volunteers search a building that collapsed after an earthquake in downtown Mexico City. (AP Photo/Rebecca Blackwell)