SIDOARJO, Indonesia (AFP) — Rescuers pulled a survivor from the ruins of a collapsed school in Indonesia on Wednesday, as desperate parents demanded searchers speed up efforts to find dozens more still believed trapped in the rubble.

Part of the multi-story school on the island of Java gave way suddenly on Monday, as students gathered for afternoon prayers.

On Wednesday, rescuers said they had retrieved a survivor and a fourth body from the ruined building.

There were no details on the survivor, but Mohammad Syafii, head of the national search and rescue agency, said the person was transferred to medics.

Based on school records “91 people are suspected to be buried,” National Disaster and Mitigation Agency spokesperson Abdul Muhari said in a statement late Tuesday.

Tearful parents milled near the ruins throughout Wednesday, awaiting news of their children.

“We believe our children might still be alive because they were crying for help,” said father Abdul Hanan, whose 14-year-old son is missing. “The rescue operation must be accelerated.”

Technology including thermal-sensing drones is being used to locate survivors and the deceased as the 72-hour “golden period” for best survival chances nears its end.

So far, signs of life have been detected in seven areas, said Emi Freezer, of the National Search and Rescue Agency. Water and food was being sent in, but access was through a single point, he said. Complicating the operation, an earthquake struck offshore overnight, briefly halting the search.

The building collapsed after its foundation pillars failed to support the weight of new construction on the fourth floor of the school, said the national disaster management agency spokesperson.