MEXICO CITY (CBSNewYork) — An urgent effort continued Thursday evening to rescue people still trapped in the rubble after the major earthquake in Mexico this week.

As CBS News Chris Martinez reported, numerous earthquake survivors were still trapped under the rubble of crumbled buildings and homes.

At least 245 people have been killed with more than 2,000 hurt by the magnitude 7.1 quake. More than 50 survivors have been pulled to safety throughout the region, but it’s a race against time as soldiers, police, firefighters and citizens dig through the debris.

The youngest known earthquake victim so far is 3 months old, and there are fears that more victims could be buried beneath buildings that were destroyed.

Lourdes Escamilla, 27, was holding out hope Thursday that her husband, Sahid, would be pulled to safety. She said he was working in an office building when the 7.1-magnitude earthquake rocked Mexico City Tuesday.

Guadalupe Salinas-Riojas was frantically searching for her 26-year-old son.

They, along with many others, have been camped out in Mexico City since Tuesday.

Earlier, a rescuer shimmied into a crawl space at a collapsed elementary school. Then with raised fists, other rescuers asked for silence so they could listen for signs of life beneath the rubble.

Crews at the school have been trying to reach a little girl who has been talking with them and wiggling her fingers. One rescuer told a reporter thermal cameras indicate several other children are also inside.

Dramatic video from Wednesday showed two students being pulled to safety through cracks in the debris. The school crumbled Tuesday during the massive earthquake, killing more than two dozen, mostly children.

Mexico City remains a dangerous place after nearly 40 buildings there have already collapsed. At one building, crews say they’re trying to prop up the remaining bottom floor with blocks of wood because they fear it could give way.

Meanwhile, power has been restored for the nearly 4 million people who lost it during the earthquake.

The Mexico City transit system is back up and running, but it will be a long time before the area struck by the earthquake is made whole.

The tragedy has also moved Mexico’s President Enrique Pena Nieto to declare three days of national mourning.

Many countries are now also extending help and aid to Mexico. A U.S. disaster relief team is now in the region, along with 60 U.S. firefighter who will help assess the damage and also look for survivors.