Rescuers and hundreds of volunteers were working nonstop Thursday to search for survivors of Mexico's deadly 7.1 magnitude earthquake.

At least 245 people were killed in the quake that struck Tuesday afternoon. Dozens were pulled out alive from collapsed buildings, including 11 at an elementary school, where rescuers worked through the night trying to free a little girl still trapped beneath the debris. They believed there could be more children inside, but time was running out.

Hundreds of volunteers joined the rescue efforts, every so often raising their fists asking for silence so first responders could listen for sounds coming from the wreckage.

"They are (there) all day, the families around the building. So they are very worried," Volunteer Alex Osorio, a banker who helped save four people from the rubble of a collapsed office building, told CBS News correspondent Manuel Bojorquez.

"It's very emotional, but also that gives us energy to work hard and to do this effort for our people," Osorio said.

Dramatic rescues happened all across central Mexico on Wednesday.

First responders continued pulling survivors from the rubble more than 24 hours after the earthquake struck. They have become symbols of hope for those still searching for missing loved ones, like Marta Laura, who prayed with a rosary for her husband of 15 years who was missing after the quake. An engineer, he had just begun a new job at a building that collapsed, Bojorquez reports.

On Thursday, more than 50 people had been pulled alive from the rubble in Mexico City, but a forecast of rain threatened to slow down rescue efforts.