Mike was working at the Carmel Ice Skadium that August evening in 2011 and the couple's young daughter, Lydia, was with Andrea's parents back home in Pendleton, a small, Norman Rockwell-type town some 30 miles northeast of Indianapolis.
It was while she was on Facebook that Sandi Voss, Andrea's mom, first learned there had been an accident at the concert. She quickly turned on the television and saw the breaking news reports that chilled her: High winds from an approaching storm had collapsed the stage rigging into the crowd. Numerous people were hurt and some were feared dead.
"It was really terrifying trying to grasp what had happened," Sandi told the Dayton Daily News. "I called Mike and by then he'd heard from Andrea's friends. They'd told him, 'We've gotten back together — but we can't find her.' One of the girls had been holding Andrea's hand when they started running . and then had lost her."
For a brief while, Sandi said she and her husband waited at home for the call that never came:
"I felt if Andrea could talk, she'd be on the phone telling Mike she was OK. More and more I had the feeling something bad had happened, so we put Lydia in the car and headed straight to Methodist Hospital in Indianapolis. It's a Level I trauma center and we'd heard the most severely injured were being taken there."
There was no record of Andrea's admittance to Methodist, but a friend from Pendleton who was a social worker there said she'd check the Jane Does that had come in.
"When she came back, she said she'd found someone, but the woman was in such bad shape she couldn't recognize her," Sandi said softly. "She asked what Andrea's wedding ring looked like and when we described it, she said, 'They're getting her ready for surgery now.'"
Seven people — including two women standing next to Andrea — would end up dying and 58 others were injured.
Andrea was one of the most seriously hurt. The right side of her skull was crushed, causing a traumatic brain injury.
She had other broken bones — including three vertebrae in her spine — and was comatose and unable to breathe on her own.
"For three weeks it was touch and go," Mike said quietly. "Right off, they told us with these types of injuries she might not survive."
As he and Sandi told the story the other day at the Vellinga home, Andrea sat on the living room couch and listened quietly, but a bit detached.
Her left arm — a black brace strapped to the wrist and hand — lay across her lap. The pink helmet she must wear everywhere had been removed and set on the coffee table in front of her, enabling you to see the damaged right side of her skull that doctors haven't yet been able to fully repair.
When she first saw photos taken of herself without the helmet, Andrea said she reacted negatively: "I was like, 'Oh gross. My head doesn't look right.'. But I knew I had to accept it. That's how I look now. And I think people will understand."
And yet, people also see she has the same radiant beauty — especially when she laughs — that she had before.
"I don't remember anything from the accident or my first weeks in the hospital," she said. "A nurse from Methodist brought me flowers when I was at RHI (Rehabilitation Hospital of Indiana) and said, 'These are for my Miracle Girl.' I thought, 'What? Miracle Girl?' I didn't understand.
"She told me my intracranial pressure was so high they didn't know if I was going to make it. . So now it makes sense. It is a miracle I survived considering how badly I was hurt."
And that's where the boot comes in.
Besides the wedding ring, she was identified by the one brown cowboy boot she wore.
"When I was growing up, we had horses," Sandi said. "These boots belonged to my dad — her grandpa — and I've kept them. They're small and when Andrea started going to country concerts, she asked if she could wear them. I said, 'Sure, as long as you take care of them and bring them back.'"
At this concert, Andrea took off one boot and handed it to her friend who was closest to the stage. She wanted her to set it up there so (Sugarland star) Jennifer Nettles would sign it.
When everything came crashing down, the girl holding the boot knew how important it was and hung onto it. Later she showed up at the hospital with it.
"That's how we knew Andrea was wearing just one boot," Sandi said. "So those boots really do have quite a story behind them now."
As Andrea headed to surgery, medical staffers removed her wedding ring and handed it to Mike.
"He kept it in his pocket every day after that," Sandi said. "And then one day when Andrea still was only semi-conscious he pressed the ring into her right hand. And even though she couldn't really respond, she slowly worked that ring around in her hand and somehow managed to get it on the ring finger of her left hand, which she couldn't move.
Mike said that first night in the hospital he was approached about enrolling his wife in a cutting-edge experimental trial that uses the pregnancy hormone progesterone to reduce swelling and improve the memory of those with traumatic brain injuries.
He agreed, and although they still don't know if she received the drug or a placebo, they think she got the hormone because Andrea's progress in many areas has been remarkable.
Surgeons have had a problem getting the plastic flap affixed to the right side of her skull. They've tried twice in the past year and each time an infection developed. She said doctors figured part of the problem is that her scalp has shrunk, so they've temporarily inserted saline-inflated expanders to stretch it back out.
There's also the challenge of her left arm. "She can move it, she just can't control it," Sandi said. "It's not paralyzed, but the right side of her brain was injured and that controls the left side of the body. But they're working on it."
Andrea nodded in agreement. "TBI's affect you in so many different ways. Some of it bothers me. I don't like being so dependent on people. I've gotten kind of negative and I never was like that before. And so for a while here, I kind of lost my initiative and didn't want to get off the couch. That's why I'm going to a personal trainer now three times a week."
And next year when her insurance kicks back in — she hit the pay-out limits this year — she'll be able to get more rehab.
In the meantime she said she deals with challenges as they come:
"My long-term memory is good, but my short term is really bad. And sometimes I just can't explain what I do."
And that brought a smile: "I never used to like ketchup, but then I went through a stage where I'd take everything — a peach, anything I was eating — and dip it in ketchup. Now I've gotten through that, but there still are little things.
"One time I was folding all of Lydia's clothes and I brought something out — a polka dot shirt — and I said, 'Sweetie, is this a pajama or a T-shirt?' She grabbed it from me and said, 'Mom!' and threw it in her pajama drawer.
"I said, 'Sweetie, that's the kind of stuff I forget.' I had no idea what I was looking at. But Lydia understands that now and she's become like my little mini-doctor. Even though she doesn't know what time it is, she'll go, 'Mom, time for your 8 o'clock meds.'
"She'll hold each pill and want to put it in my mouth. It's so cute. She just wants to help her mom get better."