A fan who was critically injured during a stage collapse at the Indiana State Fair in 2011 has undergone successful surgery to replace a portion of her skull that has been missing since the horrifying accident.

Andrea Voss Vellinga of Pendleton, Ind. suffered traumatic brain injury on August 13, 2011, when she went to see her favorite group, Sugarland. Vellinga had special passes to a VIP seating section called the Sugar Pit -- right next to the stage -- but high winds caused the temporary rigging to implode and fall into the audience. Seven people were killed and 58 others were injured. Vellinga was one of the most critically injured of the survivors, suffering multiple broken bones and skull trauma so severe that she had to be identified by her wedding ring and boots.

After three unsuccessful attempts at skull surgery, doctors were able to use skin expanders to stretch Vellinga's scalp. According to WISH TV in Indianapolis, the treatments took place every two weeks for four months. Doctors filled the expanders with saline, which Vellinga described as very painful, but worth it. Having her skin stretched allowed the doctors to complete the most recent surgery successfully, and Vellinga has been able to shed the helmet that she has had to wear for protection since her accident, though she says she sometimes grabs it out of habit.

Though Vellinga has made what some doctors have called a "miracle recovery," she still has a long way to go through extensive physical therapy. She has undergone seven major surgeries since receiving her injuries.

"I feel really good," she says. "People ask me how I am so strong; I get my strength from my mom. She has been so strong through all of this."