Around 70 teen girls were located safely after venturing into the sewer system during a school field trip in Nyack, New York on Wednesday, authorities said.

The students of Toras Emachu School in Monsey were on a school trip to Memorial Park in Nyack, about 50 miles north of New York City, when they entered the drainage culvert near the town’s central business district.

A police officer from nearby Orangetown spotted several girls exiting a sewer grate in an alley just off the main drag and alerted local authorities, according to News 12 Westchester.

All of the girls were able to safely exit the culvert on their own and no serious injuries were reported.

One student was treated at the scene, and another complaining of abdominal pain was brought to Montefiore Nyack Hospital, the outlet writes.