PETIONVILLE, Haiti—A hillside school where roughly 500 students crowded into several floors collapsed during classes on Friday, killing at least 30 people and injuring many more. Rescuers used bare hands to pull bleeding students from the wreckage.

More children were believed buried in the rubble of the concrete building, and the death toll was likely to go higher, Yphosiane Vil, an civil protection official, told The Associated Press at the scene.

Neighbors suspected the building was poorly rebuilt after it partially collapsed eight years ago, said Jinny Germain, a French teacher at the school. She said people who lived just downhill abandoned their land out of fear that the building would tumble onto them, and that the school’s owner tried to buy up their vacated properties.

The concrete building’s third story was still under construction, and Petionville Mayor Claire Rudie Parent told the AP she suspects a structural defect caused the collapse, not the recent rains.

Police commissioner Francene Moreau says the preacher who runs the church-operated school could face criminal charges.