Dale City, Va. - Cecilia Turnbough's husband says the Dale City volunteer EMT was always prepared for everything. But nothing could prepare him for her sudden death Sunday during a training exercise.

"One day, one day she's here and one day she's not," said her husband, Chris Turnbough.

Turnbough is a Lieutenant at the Dale City Volunteer Fire Department, where his 42-year-old wife died while training to join her husband, son and niece as a volunteer firefighter -- she was already a volunteer EMT.

"She loved helping, giving back. I don't know, I think she'd want others to come and volunteer and help," Chris said.

In addition to raising three children and her niece, Turnbough had worked as an EMT out of each of Dale City's firehouses over the past eight years. She recently decided she wanted to train to become a firefighter as well.

Friend Liz Ryan, herself a firefighter, recalled, "She said 'No, I'm going to take Fire One,' and I said 'Are you serious? Wow.'"

Investigators are still trying to figure out what went wrong during the training exercise on Sunday at the Prince William County (web|news) Public Safety Training Center in Nokesville. Turnbough was wearing full fire gear, including breathing apparatus, and making her way through a pitch dark maze that simulates what a firefighter might see in a house fire -- but without the actual smoke and fire.

At some point while navigating the maze, Turnbough collapsed. After her radio went silent, an instructor quickly found her and pulled her out.

"It was very quick, yes, as far as realizing something was wrong and getting her out," said Warren Whitley, an assistant chief with Prince William County Fire and Rescue.

Despite efforts to revive her, Turnbough died later at a local hospital.

Capt. Larry Houck of the Dale City volunteer fire department said, "It's not expected for something like that to happen, especially in a training environment, but our jobs are dangerous and it's one of the things we understand."

Chris Turnbough knows the drill. He, his son, and niece have all been through it. He says the risk in the maze is limited.

A thin black line is drawn across the fire department emblem on truck at Firehouse 13 in Dale City.

"Being a firefighter and going through it, I don't feel the maze had anything to do with it," he said.

"It's a little intimidating. It's dark and you're kind of thinking, 'Which way do I need to go?'" added Ryan, who has also been through the test.

The investigation of Turnbough's death remains underway. It will hinge, of course, on the results of an autopsy and the exact cause of death.

The volunteer firefighter recruit class has been suspended.

On the Net: Dale City Volunteer Fire Department