Injured third-grade teacher tells of trying to protect students

(CBS News) MOORE, Okla. -- Third-grade teacher Jennifer Doan's sternum and spine are fractured, and there are lacerations all over her body. She can barely speak, but her memory of the tornado is crystal clear.

"We told them to get down, there weren't any lights on and already and they were all scared," she says. "I held my arm -- my arm over the ones next to me ... and I looked up at the door and I put my head down and it just hit."

Jennifer says she remembers putting her arms around two of the children. Rescuers found her under the rubble of Plaza Towers Elementary School. One of the third-grade students she tried to protect was buried beside her.

Asked what she and her student were saying to each other, Jennifer says, "It was just telling him to keep calm and that they would come, and he just kept telling me that he couldn't breathe and he didn't want to die."

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"I don't know how long we were stuck, and somebody finally came and dug some stuff from above my head and they reached their hand down for me," she says.

Watch: Up-close video of Moore, Okla., tornado, below.

Jennifer never lost consciousness but was transported without knowing what happened to her students or fellow teachers. On Tuesday, she found out seven of her 20 students died.

"It's been replaying and replaying in my head," she says.

Jennifer says the little boy who was rescued moments before her has survived his injuries. She is unsure whether she will need surgery or how long it will be before she is released from the hospital.