Members of a rescue team hold a Topos search volunteer by his feet during the search for students at the Enrique Rebsamen school in Mexico City.

Caskets holding the bodies of quake victims are arranged in a grave in Atzala, on the outskirts of Puebla, Mexico.

Workers carry a tube during the search for students at Enrique Rebsamen school after an earthquake in Mexico City, Mexico, September 20, 2017. REUTERS/Edgard Garrido - RC1957DC9C30

Volunteers and rescue workers search for children trapped inside the Enrique Rebsamen school in southern Mexico City on Wednesday. A wing of the three-story building collapsed into a massive pancake of concrete slabs. The school's rooftops bore messages that called for silence and for no helicopters to fly over, so as not to drown out the sounds of anyone who may trapped in the rubble.

Rescue workers search through the rubble for students at Enrique Rebsamen school after an earthquake in Mexico City, Mexico, September 20, 2017. REUTERS/Edgard Garrido - RC141C69CBB0

Rescue workers and volunteers search for survivors in a building felled by Tuesday's earthquake, in the Colonia Obrera neighborhood of Mexico City. A mix of neighborhood volunteers, police and firefighters used trained dogs and their bare hands to search through the ruins.

Rescue workers search for people trapped in a collapsed building in the Piedad Narvarte neighborhood of Mexico City on Wednesday.

A man is rescued from a collapsed building in the Condesa neighborhood of Mexico City after the 7.1-magnitude earthquake Tuesday.

A pay phone is surrounded by rubble after a magnitude-7.1 earthquake, in Jojutla, Morelos state, Mexico, on Wednesday.

Residents salvage personal items from a damaged home Wednesday in Jojutla, Morelos state, Mexico.

A collapsed building sits on a crushed car Wednesday in Jojutla, Mexico, Wednesday.

Volunteers and rescue workers search for children trapped inside a collapsed wing of the Enrique Rebsamen school in southern Mexico City Wednesday. The school's rooftops and facade bore messages calling for silence and for no helicopter flyovers, so as not to drown out the sounds of anyone who may still be alive in the rubble.

Rescue workers and volunteers search for survivors in the aftermath of a magnitude-7.1 earthquake, in the Ninos Heroes neighborhood in Mexico City on Tuesday. Workers, some wearing helmets, sometimes called for silence as they tried to listen for survivors.

A building demolished by the earthquake in Jojutla, Morelos state, Mexico, Wednesday.

An injured man is pulled out of a building that collapsed during an earthquake in the Roma Norte neighborhood of Mexico City.

A man walks out of the door frame of a building that collapsed after an earthquake in the Condesa neighborhood of Mexico City on Tuesday.

A woman tries to reach others on her cellphone after an earthquake in Mexico City on Tuesday.

Volunteers search a building that collapsed after an earthquake, in the Roma neighborhood of Mexico City on Tuesday.

A car sits crushed, engulfed in a pile of rubble from a building felled by Tuesday's earthquake in Jojutla, Morelos state, Mexico.

Hospital patients lie on their beds after being evacuated following an earthquake in Mexico City on Tuesday.