OFFICIALS

are three more floors to remove rubble from. And you still hear people in there," said Evodio Dario Marcelino, a volunteer who was working with dozens of others at a collapsed apartment building.

A man was pulled alive from a partly collapsed apartment building in northern Mexico City more than 24 hours after the Tuesday quake and taken away in a stretcher, apparently conscious

In all, 52 people had been rescued alive since the quake, the city's Social Development Department said, adding in a tweet: "We won't stop." It was a race against time, Pena Nieto warned in a tweet of his own saying that "every minute counts to save lives."

People have rallied to help their neighbors

in a huge volunteer effort that includes people from all walks of life in Mexico City, where social classes seldom mix. Doctors, dentists and lawyers stood alongside construction workers and street sweepers, handing buckets of debris or chunks of concrete hand-to-hand down the line.

At a collapsed factory building closer to the city's center, giant cranes lifted huge slabs of concrete from the towering pile of rubble, like peeling layers from an onion. Workers with hand tools would quickly move in to look for signs of survivors and begin attacking the next layer.

In addition to those killed in Mexico City, the federal civil defense agency said 69 died in Morelos state just south of the capital and 43 in Puebla state to the southeast, where the quake was centered. The rest of the deaths were in Mexico State, which borders Mexico City on three sides, Guerrero and Oaxaca states.