San Antonio fire crews have rescued an 18-year-old LEE High school student who got stuck in a cave during a field trip.

The rescue happened just before midnight Thursday after more than 10 hours of entrapment.

"She told her mom, 'I didn't want to die in there.'" San Antonio Fire Chief Charles Hood said.

"We had a plan, and fortunately Plan A worked out for us. It was very difficult to chip away at that rock," he said.

Firefighters were called to the Robber Baron Cave at around 2:40 p.m. Thursday. The cave is located on the city's north side off Nacogdoches Road, just south of Loop 410 and the San Antonio International Airport.

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"She is conscious. She is alert. She is a trooper," San Antonio Fire Chief Charles Hood said around 10 p.m. as the rescue continued. "She is in very good spirits considering what she has been through."

The young woman was with a group of students on a field trip when she somehow got stuck in a narrow area called the “hole in the floor.” That spot is about 350 feet inside the cave.

The experienced cavers who were with the students at the time worked for about an hour to try to free her, then contacted emergency personnel to come to the scene.

Those crews were able to reach the girl, and they were keeping her warm and hydrated throughout the ordeal. She was not believed to be hurt, but she was being taken to the hospital after her rescue as a precautionary measure.

The effort to get her out of the cave stretched well into the late evening hours. Hood said there were about 70 rescuers on scene and that they were working in 20-minute shifts in the tight space inside the cave.

The temperature inside the cave is actually warmer than outside, about 75 degrees and musty, Hood said.

"We have to be prepared for a long operation," Hood said earlier in the evening. Rescuers were gradually chipping away at the rock around her and have taken measures to make sure that she did not slip further into the rock formation, which potentially could have impeded her breathing.

"We have paramedics and firefighters with her," he said. "She is never by herself."