AGUAS BUENAS, P.R. — Natalia Hernández stood before dawn with a bullhorn in her hand in front of the mountainside elementary school that four generations of her family attended, rattling off its academic accomplishments.

More than half the pupils are on the honor roll. There are tutors, a social worker and even a speech therapist, she said. But there has been an exodus of families from Puerto Rico in the face of its economic collapse, so little Luis Santaella School has a big problem: Only 146 children are enrolled compared with about 250 in the past.

And so, like 178 other schools across the island, it is set to close after the last day of the school term this week, in part to help Puerto Rico battle debt and pension obligations of $123 billion. The school, perched alongside a winding two-lane road 1,400 feet above sea level, will join the many casualties of a fiscal crisis that forced Puerto Rico to declare a form of bankruptcy last week and sent hundreds of thousands of people packing in the past decade.

The school will join the shuttered businesses and abandoned homes as yet another indicator of the emergency gripping Puerto Rico and the desperate efforts to stop the hemorrhaging. For some, the closings represent not just another chip at Puerto Rico’s national budget, but also an opportunity to transform a struggling education system in which some schools are infested with termites, enrollment has dropped by nearly a third since 2010, and just 10 percent of eighth graders passed the standardized math test.