Philippine rescuers were racing against time on Monday in a search for possible signs of life more than 24 hours after the collapse of a building under construction in the city of Angeles, with crews carefully removing rocks and surrounding debris by hand.

The painstaking manual operation around 80 km (50 miles) north of the capital Manila underscored the difficulty of the rescue effort, ‌carried out under scorching heat, with authorities unable to rely on excavators and other machinery for fear that the unstable structure could shift further and bury any survivors deeper beneath the wreckage and rubble.

As search operations stretched into a second day, families waiting near the disaster area voiced growing frustration and despair, saying they were receiving no information about the fate of their missing loved ones. “My youngest child keeps asking, but I do not have answers,” said 47-year-old Lea Casilao, whose husband, a construction worker, is believed to be trapped beneath the rubble.

“If ⁠only the rescuers could call out his name, he might still respond, so I’d have something to hold on to, some hope,” Casilao said, wiping ‌away her tears.

Search teams, assisted by K9 dogs, continued to comb through the debris after overnight thermal scans detected heartbeats and breathing beneath the collapsed structure.

Rescuers also placed yellow flexible tubes to channel air into pockets beneath a tangle of ‌concrete, mangled metal and collapsed scaffolding.