Teachers and students at Plaza Towers Elementary School hunkered down against the storm just as they had been taught in countless tornado drills, their principal said Friday, recounting how she walked the halls until the twister was on the doorstep, then announced on the intercom, "It's here."

An aerial view of the Plaza Tower elementary school after a powerful tornado ripped through Moore, Okalhoma
An aerial view of the Plaza Tower elementary school after a powerful tornado ripped through Moore, Okalhoma (Benjamin Krain/Getty Images)

In a pause-filled recollection that left many weeping, Amy Simpson said at a news conference that her teachers emerged battered after doing what they could to save every child in the Oklahoma school. Still, seven second- and third-graders were among the 24 killed when the top-of-the-scale EF5 tornado with 210 mph winds struck Moore on Monday.

"The teachers covered themselves in debris while they were covering their babies. And I believe that is why so many of us survived that day, because the teachers were able to act quickly, stay calm and take literally the weight of a wall onto their bodies to save those that were under them," said Simpson, a native of the city of about 56,000.

The tornado was on the ground for 40 minutes and left a 17-mile path of destruction.

Its victims at the school were ages 8 and 9.

"These kids are close. They grew up in one neighborhood. They play in the streets. They play in the creek. They have their own little community, even more so in the classroom," second-grade teacher Emily Eischen said.

The Moore School District canceled its school year after the tornado hit Plaza Towers and the Briarwood school, where all students survived. District officials and teachers met with pupils and their parents Thursday to give everyone a chance to say goodbye before heading into summer vacation.

Debris covers the grounds of the Plaza Towers Elementary School
Debris covers the grounds of the Plaza Towers Elementary School (Scott Olson/Getty Images)

Simpson said that, having been born and raised in Oklahoma, she knew what it meant to deal with tornadoes. The state, in the heart of Tornado Alley, has averaged more than 50 tornadoes per year since record-keeping began in 1950.

"Not one parent blamed us because they're Oklahomans, too, and they know what a tornado means and they know what it means in school," Simpson said. "We practice our procedures. We get in our safest places."

Simpson said teachers and students had spent much of Monday morning celebrating their achievements and practicing this year's sixth-grade graduation.

Then attention turned to the sky.

When the sirens blared, the principal walked the school to make sure everyone was prepared.

"Teachers were rubbing kids on the back, singing songs," while the students were crouched with their hands behind their necks, Simpson said.

When Simpson got to her office, a fifth-grade teacher told her the storm was just southwest of the school. "I got on the intercom and said, 'It's here,'" Simpson said.

She rode out the storm in a bathroom.

"You feel things trickling down on you from the ceiling, then those things become chunks of things," Simpson said. "I yelled and said, 'In God's name, go away!' I yelled it about four times. And then it was gone."

While debris was still flying, Simpson said, she told others, "I've got to get to the kids. I got out of the bathroom and the whole neighborhood was gone."

Plaza Tower School before & after
Plaza Tower School before & after (Daily Mail)

She quickly tended to the younger students then saw that students in grades 4, 5 and 6 were heading to a nearby church. She asked her husband to help the second- and third-graders — she hadn't seen any of them yet.

They were in a part of the school that was particularly hard-hit. School counselor Kristin Atchley said surviving class members could tell while still trapped in the rubble who wasn't going to make it.

"They knew before they got pulled out," Atchley said.