MEXICO CITY _ Scenes of desolation and rejoicing unspooled Thursday at the sites of buildings crumbled by Mexico's deadly earthquake, which killed at least 252 people and galvanized heroic efforts to reach those trapped, including a child or children thought to still be alive in the ruins of a school.
Battling grinding fatigue and mountains of rubble, rescuers in three Mexican states raced against time in the search for survivors, keenly aware of ever-dwindling odds of finding people alive beneath the debris.
Those killed in Tuesday's devastating magnitude 7.1 temblor included dozens of schoolchildren, and the overall confirmed fatality count was expected to climb as more bodies were recovered.
Approaching the 48-hour mark since the quake, rescuers at sites across the sprawling metropolis of Mexico City used search dogs and calls to the cellphones of those trapped inside to try to pinpoint the location of anyone who had survived two full nights under the remains of damaged buildings.
The harrowing and intensely chronicled rescue effort at the Enrique Rebsamen school in the capital became a social media sensation when Mexican news outlets identified a trapped girl, with whom rescuers had managed to make contact, as "Frida Sofia." By Thursday afternoon, authorities said that at least one boy or girl was believed to be alive in the wrecked building but that they were not sure of the child's name.
Efforts to reach the child or children stalled early Thursday as the rubble shifted and had to be shored up. In the early hours after the quake, 11 other children had been rescued at the scene, and a woman's body was recovered early Thursday.
For many, the fate of one little boy or girl became a symbolic stand-in for a panorama of loss, either threatened or realized. Even for those without casualties in their circle of family and friends, widely shared news of the rescue effort at the school provided a national commonality after the quake had robbed so many of any sense of safety and normalcy.
Outside quake-wrecked buildings, successful rescues heartened everyone. Cheers erupted overnight at the site of a collapsed multistory office building in the neighborhood of La Condesa where rescuers pulled three people alive from the rubble, witnesses said. More were believed still trapped, authorities said.
Shows of solidarity were everywhere. On Thursday morning, volunteers armed with shovels lined up near the rescue site to relieve those who had been moving rubble all night. Other volunteers handed out coffee, sandwiches and chilaquiles _ a popular Mexican breakfast dish _ to dust-covered rescuers.
A continual stream of cars pulled up at makeshift donation centers: ordinary people dropping off food, water, gloves, hard hats and protective face masks.
President Enrique Pena Nieto, who has declared three days of national mourning, on Thursday paid a hospital visit to those injured in the quake.
An elite team of disaster experts, including an urban search-and-rescue team from the Los Angeles County Fire Department, landed in Mexico City to aid in relief efforts.
The U.S. Agency for International Development, known as USAID, reported the arrival of its Disaster Assistance Response Team, along with more than 60 firefighters and five highly trained dogs.
The USAID team, requested by the Mexican government, will conduct damage assessments, search for victims and coordinate with local authorities and aid groups to bring assistance to those most affected.
As dawn broke, rescue efforts pushed ahead in neighborhoods rich and poor. Hours earlier, in La Condesa, a woman's faint voice could hardly be heard under a pile of rubble that had been her second-story apartment. Rescuers thought there could be up to four people under the collapsed ruins.
Standing atop the building's remains Wednesday night, firefighters, soldiers and volunteers peeled back entire floors in slices, digging past people's belongings: books, blankets, clothes, an ironing board. Couches and pillows went flying.
The rescuers demanded silence. One of them stuck his head down into the void, calling for anyone there to answer if they could. But it was still too loud. Generators and vehicles were turned off. Small chatter subsided.
"We need absolute silence," the worker said. "Please."
From a few dozen yards away, the voice sounded like a whisper. The rescuers waited. The trapped woman called to them again.
People stood still, captivated. Some of them wept. A woman broke the silence, yelling over a megaphone: "She is Lorna. She's on the second floor."
The woman said Lorna's family was trying to call her. Seconds later, a phone chimed from inside the pile.
After Lorna spoke, the workers quickened their pace, passing buckets of concrete down lines of volunteers to a truck for disposal. A storm had come into the city around 7:30 p.m., pummeling the site with rain for several minutes. Thunder crackled, and lightning flashed.
At 5 a.m., rescuers recovered another body from the building: that of Gabriela Jaen Pimienta, 44 _ found hugging her Chihuahua, also dead. She had lived on the fifth floor with her husband and daughter, who both survived the earthquake, said relatives who had kept a day-and-night vigil.
In parts of the city, life appeared to be returning to normal Thursday. People stood in front of their homes, sweeping away leaves that had fallen in the overnight rainstorm. Mexico City's famous tamale vendors were back on the streets, hawking their wares from the backs of bicycles.
But neighborhoods more affected by the quake looked like war zones. Large army trucks lined a popular thoroughfare. Soldiers guarded a park where rescue efforts were being coordinated.
Many rescuers had worked through the night. The lucky ones had slept a little in soggy tents assembled in the park.
