Cecilia Turnbough, 42, died during a routine training exercise as part of an entry-level firefighter certification class, according to the fire department.
Turnbough, a certified EMT, had served as a volunteer firefighter for eight years. She recently began training to expand her capabilities to include firefighting.
The training she was taking part in Sunday involved maneuvering through a maze. Authorities said she was wearing her fire gear and was crawling through the maze when she stopped communicating with instructors. When they went in after her, they found her unconscious.
Turnbough was transported to a nearby hospital, where she was treated and later died.
There was no smoke or fire during the training. Fire officials said they don't know if her death was related to the training exercise. A full investigation and an autopsy will be conducted.
Her husband, Chris Turnbough, is a lieutenant for the Dale City Volunteer Fire Department. She has three children, including one who is serving in the Navy overseas.