MEXICO CITY — Rescuers searched massive piles of rubble for any signs of life Wednesday after dozens of buildings collapsed across central Mexico in a violent earthquake, which killed at least 230 people, injured at least 1,000 and caused chaos in Mexico's capital.
Firefighters, soldiers and volunteers had worked through the night clearing debris and scrambling to find survivors, at times working with bare hands and donated flashlights. There were a few moments of relief when several still-breathing, dust-covered survivors were pulled from the wreckage and transported to hospitals. But many others were found dead.
Some of the most heart-wrenching scenes played out at a three-story school that pancaked into a pile of rubble on the south side of the city. Rescue workers pulled at least 25 bodies from the ruins, all but four of them children.
Five people were killed at the Mexico City campus of the Monterrey Institute of Technology and Higher Education, the school said in a statement. Scores more died in collapsed apartment buildings and office towers.
The magnitude 7.1 earthquake, which struck early Tuesday afternoon, was the second powerful temblor to hit Mexico in less than two weeks. President Enrique Pena Nieto declared three days of national mourning to honor the victims.
"I want to express my condolences to those who lost a family relative or loved one," he said in a video statement to the nation late Tuesday. "Mexico shares your pain."
With 40 percent of Mexico City without power, and glass and debris strewn across the capital, many residents will need help in the coming days, he said, but the first priority was to rescue those still trapped under the rubble and provide medical care to the injured.
"As Mexicans, we have experienced difficult times because of earthquakes in the past, and we have learned to respond with dedication and spirit of solidarity," he said.
President Donald Trump had a lengthy phone call with his Mexican counterpart Wednesday, White House press secretary Sarah Huckabee Sanders said.
As of Wednesday evening, the death toll stood at 230, according to a tweet from Luis Felipe Puente, Mexico's national coordinator for civil protection. They included 100 people killed in the autonomous district of Mexico City, 69 in Morelos, 43 in the state of Puebla and 13 in Mexico state. There were four deaths in Guerrero state and one in Oaxaca state.
At least 800 people were injured in Mexico City alone.
Amid the chaos of an all-night rescue operation at one collapsed office building — as ambulances circled with sirens blaring and firefighters desperately searched the rubble for survivors — a group of several dozen people pressed against police tape, watching in anxious silence.
They were the mothers, sisters, cousins, husbands and wives of people trapped inside the wreckage of the multistory building, located in the upscale neighborhood of Condesa, in the center of Mexico City.
Conception Chavez Lopez, 51, had been waiting outside for seven hours.
She had seen more than a dozen people pulled alive from the wreckage. None had been her son, Gustavo Banda Chavez, 23, or her brother, Miguel Angel Chavez Lopez, 48, who worked together in an accounting company on the building's fourth floor.
Chavez could barely utter her own name when someone asked it shortly before midnight Tuesday. She and a small group of relatives kept their eyes desperately trained on the scene in front of them: firefighters picking their way across a towering heap of bricks, chunks of concrete and twisted metal, their work illuminated by floodlights.
Tuesday's earthquake jolted the capital city on the anniversary of a deadly 1985 temblor in the region.
Across the region, authorities begged for donations of food and water to help nourish rescuers and for flashlights to help light the searches that likely would go into Wednesday night.
All Alejandro Santiago hoped, as he stood watching the office building in Condesa late Tuesday, was that somebody would say the name of his 28-year-old cousin: Paulina Gomez. That's all he wanted to hear.
It would mean that somebody had found Gomez, a human resources administrator who worked on the fourth floor, somewhere down there beneath the rubble. It would mean her name could join the list of people who had been rescued that authorities were writing on a piece of poster board attached to a light post.
But Santiago, 28, had been there two hours and hadn't heard anything. So he waited, and watched. At one point, police had asked the family members to move farther from the scene. They refused.
"We're not moving until we find out what happened to them," he said.
Miguel Angel Pimienta Avalos, 63, arrived outside a collapsed apartment block in Condesa at 10 p.m. Tuesday hoping to find his niece, who lived on the fifth floor of the six-story building.
When the quake hit, he had called every family member to make sure they were safe. She was the only person who didn't answer.
"When I saw the photos on the internet, I said, 'It's not likely that they'll get people out,'" he said, looking away as he fought back tears. "Hopefully there is a miracle."
Just across from the apartments, medics had turned a building for representatives from the state of Durango into a makeshift base for family members of the missing. Members of 13 families had signed in throughout the night. None of their loved ones had been found by morning, and most had left by daybreak.
Ten hours after he arrived, Avalos was the only one left, volunteering to pass the time, and praying to God.
Nurses set up a sidewalk clinic, while others walked around offering pastries and water. Dozens of people stood watch, their mouths covered with face masks, as volunteers atop a mountain of rubble passed debris down in buckets. Others carted rubble away from the ground in wheelbarrows.
One rescue worker brought a yellow Labrador retriever to the top of the pile to sniff out bodies. Suddenly, workers dimmed the lights, cut off the generators and called for silence. They listened. A few minutes later, they resumed their work.
Dr. Karen Pina Fragoso, who was working at the scene, said a handful of people had survived the collapse. Two walked out on their own Tuesday night, and three or four were rushed to a hospital. She didn't know how many adults remained missing in the building, but said at least three children were unaccounted for.
Fragoso said medics could still hear the voices of many survivors trapped in the building at 3 a.m. But as daylight broke, the voices quieted.
Mexico sits in one of the world's most seismically active areas, as the floor of the Pacific Ocean south of the country is sliding underneath the North American plate.
Tuesday's quake struck 32 years to the day after another powerful temblor that killed thousands and devastated large parts of Mexico City, an anniversary that had been commemorated with a citywide drill earlier in the day. . The epicenter was about 80 miles southeast of Mexico City, in the state of Puebla.
Mexico City is prone to major damage in earthquakes because it was built on a dried up old lakebed. The soft soil amplifies the shaking.