Published: Apr 18, 2011 8:04 PM EDT
Updated: Apr 18, 2011 5:05 PM EDT

CHASSAHOWITZKA, Fla. - Authorities are investigating the death of a University of South Florida student who had to be pulled from an underwater cave in central Florida.

The Citrus County Sheriff's Office says 22-year-old Amy Ryan of Palm Bay had been diving Sunday with her boyfriend and another couple. Ryan had followed her friends through the underwater caves off Chassahowitzka on Florida's Gulf coast, but she failed to surface.

Ryan's friends were unable to find her in the water. The sheriff's office says a county firefighter with rescue diving experience located Ryan and pulled her from the cave where she was lodged.

Ryan was pronounced dead at a Hernando County hospital.

(Copyright 2011 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)