MOORE, Okla. - The principal's voice came over the intercom at Plaza Towers Elementary: A severe storm was approaching and students were to go to the cafeteria and wait for their parents to pick them up.

But before all of the youngsters could get there, the tornado alarm sounded.

The plan changed quickly.

"All the teachers started screaming into the room and saying: 'Get into the hallway! We don't want you to die!' and stuff like that," said sixth grader Phaedra Dunn. "We just took off running."

At least seven pupils were killed by the twister Monday. Others would crawl out of the rubble, bloodied and bruised but alive.

The tornado destroyed Plaza Towers and also slammed Briarwood Elementary, where all the children appear to have survived. Students and parents recounted stories Tuesday of brave teachers who sheltered their pupils.

After the tornado alarm went off, students at Plaza Towers scrambled into the halls. But the halls - some within view of windows - did not appear safe enough.

Sixth grader Antonio Clark said a teacher took him and as many other youngsters as possible and shoved them into the three-stall boys' bathroom.

"We were all piled in on each other," the 12-year-old said.

Twenty seconds later he heard a roar that sounded like a stampede of elephants. His ears popped.

It stopped almost as suddenly as it started. Crouched down, his backpack over his head, Antonio looked up. The skylight and the ceiling were gone, and he was staring up into a cloud filled with debris.

He and a friend were among the first to stand up. They climbed over debris where their classroom had been moments earlier. Students and teachers were struggling to free themselves from under the bricks, wooden beams, and insulation. Some had bleeding wounds.

"Everybody was crying," Antonio said. "I was crying because I didn't know if my family was OK."

Then he saw his father ride up on a mountain bike, yelling his son's name.

At Plaza Towers, several students were pulled alive from under a collapsed wall and other heaps of mangled debris. Rescue workers passed the survivors down a human chain of parents and neighborhood volunteers. Parents carried dazed and terrified children in their arms to a triage center in the parking lot.

At Briarwood, students also went into the halls. But a third-grade teacher didn't think it looked safe, so she herded children into a closet, said David Wheeler, one of the fathers who tried to rush to the school after the tornado hit.

The teacher shielded Wheeler's 8-year-old son, Gabriel, with her arms and held him down as the tornado collapsed the school roof and started lifting students, Wheeler said.

"She saved their lives by putting them in a closet and holding their heads down," Wheeler said.

It took nearly three hours for father and son to be reunited.

Other parents waited even longer, as they drove from one emergency shelter to another.