Parents from the Enrique Rebsamen primary and secondary school in Mexico City waited in fear as rescuers searched the rubble from the three-story structure that collapsed Tuesday in a 7.1 magnitude earthquake.

As of early Wednesday, the bodies of 21 children and four adults had been pulled from the debris. Many others remained missing.

Noises could be heard from beneath the concrete, glass and twisted metal — although rescuers were unsure if it was children crying for help or the structure shifting.

Soldiers attempted to secure the remaining wing of the school by wedging wooden beams into the structure.

[lz_ndn video=33005186]

A group of extraordinary individuals moved in once the beams were set. Among them was 29-year-old Pedro Serrano, a doctor who made his way through the debris to look for any survivors.

“We dug holes, then crawled in on our bellies,” he said.

“We managed to get into a collapsed classroom. We saw some chairs and wooden tables,” Serrano added. “The next thing we saw was a leg, and then we started to move rubble and we found a girl and two adults — a woman and a man.”

The rescuers left the bodies behind as none of them were alive and freeing them was impossible.

Related: Faith-Based Groups Step Up Big-Time for Hurricane Victims

Who do you think would win the Presidency?

By completing the poll, you agree to receive emails from LifeZette, occasional offers from our partners and that you've read and agree to our privacy policy and legal statement.

Volunteers worked through the night to check for any survivors, occasionally asking for silence so they could listen for signs of life.

Tuesday’s earthquake marked Mexico’s deadliest earthquake in decades as the number of confirmed deaths climbed to 217.

This Fox News piece is used by permission; the Associated Press contributed.

Read more at Fox News:
Mexico Stirs Up World’s Largest Batch of Guacamole at 6,600 Pounds
Swimwear CEO Posts ‘Reality vs. Instagram’ Photos to Highlight the Power of Editing
Chick-fil-A Gets Caught in Hilarious Feud with Alabama Barbecue Restaurant