SAN ANTONIO (CBS NEWS/AP) — Emergency personnel have safely rescued an 18-year-old girl who was trapped for about 10 hours in a South Texas cave during a high school field trip.

Experienced cavers, who were with the students at the time, worked for about an hour to try to free her and then contacted emergency personnel.

San Antonio Fire Department Chief Charles Hood says the girl was extricated late Thursday night and transported to a hospital for evaluation, as a precaution. Hood says the Lee High School student was conscious and alert during the ordeal at Robber Baron Cave. “She told her mom, ‘I didn’t want to die in there.'”

Hood said there were about 70 rescuers on scene and they worked in 20-minute shifts in the tight space in the cave. “We had a plan, and fortunately Plan A worked out for us. It was very difficult to chip away at that rock.”

The Texas Parks & Wildlife Department says the maze cave, in north-central San Antonio, has almost a mile of passage.

(credit: Texas Cave Management Association)

Officials say the teen, whose name wasn’t immediately released, became lodged in a small area known as Hole in the Floor, with passage requiring going through a circular opening. Rescuers said the girl’s torso became stuck, but they were able to keep her warm and hydrated and make sure she didn’t slip further into the rock formation, which could have impeded her breathing.

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)