May 22, 2013 -- Dena Clark wasn't supposed to be at the Tinker Federal Credit Union in Moore, Okla., when the tornado hit Monday. Her worried mother knew a storm was coming and was on the phone with Clark telling her to go home.
But living in Oklahoma, Clark had seen so many tornadoes come and go with minimal effect that she decided to stop at the bank because she had a lot of cash in her car from a weekend garage sale at her home.
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Clark, 23, was in the middle of a transaction with a bank employee when tornado sirens started going off.
"We're actually going into the vault," the teller told Clark.
"Me too?" she asked.
"Yes," the woman replied.
For the next few minutes, the bank employees and their customers all moved into the bank's vault, a small room filled with deposit boxes and encased in two feet of concrete. The bank manager and a police officer monitored the situation by watching TV and looking out the window. At least one passerby came into the bank seeking shelter.
Clark was texting her husband about whether she should stay or go. At first he told her she could probably head out, but that text was quickly followed by another one: "Tornado on the ground. Stay."
Soon enough, the lights flickered, the TV went off and the power was out.
"Eventually, everyone was in the vault and the bank doors were closed," Clark said. "We had our flashlight and there's several people in there ranging from a 10-year-old boy on his iPad to these elderly people that just happened to be at the bank."
There were 14 employees and eight other people in the vault. There was one problem: They couldn't get the vault door closed all the way from the inside. Someone took off a belt and looped it through an opening meant to let in oxygen so that they could tug the vault door closed as much as possible, she said.
When it still wouldn't close all the way, the branch manager, the police officer and another employee held the door shut "just in case."
"After our ears started popping, I just remember hearing the windows blow out," Clark said. "I could hear the glass hit the ground. It was still relatively calm for a little bit after that but you could hear things."
"They say [a tornado] sounds like a freight train coming, and I agree with that. But it also just sounds like swirling," she said. "We could hear things moving above us, rotating above us. Things started to hit the bank vault."
The bank manager, she said, was shouting, "Don't let go! Don't let go!"
Another bank employee prayed in Spanish, crying out to God to protect them. Clark recalled getting emotional for the first time, she said, at the memory.
"You see movies. I could just picture in my mind the bank vault door ripping away from us and not knowing what was going to happen," Clark said. "I don't know how they kept that bank door shut. I don't know how long we were actually inside the tornado. It felt like forever."
Debris started flying through the cracks of the door and glass cut the feet of people who were wearing sandals. Clark said it became difficult to breathe because of all the dust and debris.
"As soon as the tornado passed, we were all kind of wondering, 'Is there a building out there?'" she said.
When they believed the twister had passed and tried to open the door, they found that they couldn't and began to smell gas.
"We started smelling gas and I was thinking to myself, we survived a tornado and now we're going to explode," Clark said.
The few people with cellphone service who had been calling and texting loved ones then called 911 to say that they were trapped in the bank vault and could smell gas.
Before authorities could arrive, people passing by heard them shouting and came to help.
"They started to dig us out and they pulled back some of the rubble just enough for us to open the door and get out," Clark said. "We made it out of the vault and it was just a sense of relief and people were hysterically crying and hyperventilating."
What she saw shocked her.
"It was unbelievable," she said. "I know it was a miracle. Nothing in the bank was standing except for where we were."
They had been in the vault for just under an hour, Clark said.
Clark's cellphone battery was running low, but she managed to text her husband, call her mother and snap a photo of the vault before the phone died.
"I believe I found my car. It's what looks like my car. It was standing vertically against some rubble," Clark said. "It's not a big deal. It can be replaced. Lives can't."
Bank officials expressed a similar sentiment.
"Thank you all for your support as we and many of our members found ourselves in the path of yesterday's storm," the bank posted on its Facebook page. "Sadly, our Moore branch was lost. Fortunately, all employees of that branch emerged unscathed, having ridden out the storm in the safety of the vault."
Hours after the tornado, Clark was reunited with her family and found that her house was relatively unscathed.
Clark said she feels "so lucky and so blessed" to have survived the disaster.
"I wasn't supposed to be at the bank," an emotional Clark said. "It was so clearly orchestrated by God."