By Becky Bratu, Kate Snow, Tim Uehlinger and Jay Kernis, NBC News
As she tours the husk of Plaza Towers Elementary School in Moore, Okla. -- the little that was left behind after a powerful tornado shredded everything in its 17-mile path -- Principal Amy Simpson thinks back to Monday morning, when her biggest task was helping the sixth-graders get ready for their graduation ceremony.
Pre-K teacher Linda Patterson and aide Kaye Johnson were working on report cards, while kindergarten teacher Erin Baxter was having her 6-year-old students write about the weather.
Four miles to the east, Susie Price began the last week of her 41-year career in public education preparing her retirement speech, getting ready for graduation -- and watching the sky for any possible threats.
“That’s what we do in Oklahoma on those days,” Pierce, the Moore Public Schools superintendent, told Rock Center’s Kate Snow.
Hours later, a Category EF5 tornado would touch down killing 24 people, injuring more than 370and destroying as many as 13,000 houses.
Sixteen minutes. That was how long Pierce had to prepare between the time she heard that a tornado had hit the ground and the time Moore was in the middle of it.
“It's not a lot of time,” she said. “But because I know these people and I know everybody that works in our district. … we've been through this before. I know that they know what to do.”
“This is part of our reality,” Pierce added.
Simpson was on alert after receiving an email from the district office about an incoming storm. Not long after, she heard the thunder.
The storm began getting heavier with hail that pummeled the school’s skylights. Then sirens started going off.
It’s not uncommon to hear sirens in Oklahoma, but she knew she couldn’t take any chances.
“Get into your places,” Simpson said over the school’s loudspeaker system.
“They know exactly what that means,” she said. “It means hallways, bathrooms, the safest places in the building."
The kids got on their knees. They put their heads right up against the hallway brick wall and covered the backs of their necks with their hands and their heads with their backpacks. To keep calm, teachers led them through the ABC song and “Twinkle, Twinkle, Little Star.”
Baxter, the kindergarten teacher, could hear the storm coming.
“It’d get louder. And you'd think it would be about to hit. And then it'd just get louder and just louder,” she recalled.
By that point, teachers were using their bodies to protect the children. Right before impact, Simpson got on the loudspeaker one last time.
“It’s here,” she remembers saying, before quickly ducking into a bathroom as the tornado smashed into the building.
“At first, it's just a rattling, like someone walking on the roof. And then you feel things fall into your hair. Just little things, you know? Nothing more than if somebody was up there fixing the air conditioning unit,” she said. “And it's -- but then all of a sudden-- bigger things. Could hear the air duct crash down and a pipe. … And that's when I started to yell.”
"In God's name, go away. Go away,” Simpson remembers yelling.
As she climbed out of the debris, Simpson noticed most of the walls around her were gone.
In a different part of the building, Patterson, the pre-K teacher, was pinned under a wall, some 2-by-4s and a car the tornado had spun up and dropped on top of the collapsed wall.
“I'm hearing the child under me saying, ‘I'm not breathing. I can't breathe,’ because I had weight on her, you know?” Patterson recalled.
“That's where I needed to be. I needed to be between that debris and those children,” she added.
Rescuers poured into the school, pulling kids and teachers from the debris, but Simpson noticed none of the third-graders had come out.
Third-grade teacher Jennifer Doan, who was just finishing her second year in the classroom, had just found out she was pregnant. Now Doan was shielding two boys with her body, trying to hold up a collapsed wall, Superintendent Pierce said.
“The little boy said, ‘Can't breathe. I don't want to die.’ And as [Simpson] said, they pulled Miss Doan out and that little boy,” Pierce said. The second little boy was buried by debris and didn’t make it.
Simpson said Doan could hear other children crying. “And she was hearing crying, and crying, and crying. And then after the tornado, the crying stopped. And it's -- what she said was, ‘The crying was horrible, but when it stopped, it was worse.’”
Of the seven children who died at Plaza Towers Elementary, six were in Doan’s class. The teacher suffered multiple injuries, but her unborn child is fine. Her friends say she’s been told about the children’s deaths and is overcome with grief.
“God makes our choices for us long before, and he had a plan long before,” Simpson said. “And those little ones, there was no control over it. There wasn't a safer place. There wasn't a better place. There wasn't anything different that Miss Doan could do.”
This weekend, bulldozers will roll in to clear away what remains of Plaza Towers Elementary – but Simpson said the only way to move on and process the loss is to rebuild.
“We have a million and one things to do,” she said. “So staying busy is a big part of that.”
Editor’s Note: If you would like to help the Moore Public Schools, click here ( www.Fundly.com/moorepublicschools ) or write to this address:
Moore Public Schools Tornado Relief Fund
1500 SE 4th
Moore, OK 73160
NBC News' Sylvie Haller, Sabrina Esposito, Jessica Kerry and Michelle Kessel contributed to this report.
