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Parents, teachers and students desperately pleaded for authorities in 911 calls to race to Marysville Pilchuck High School north of Seattle after a lone shooter fired upon his peers, with one of them imploring, "I need help."

"I'm in the cafeteria. I have the shooter. One shooter," a woman who identified herself as Megan Silberberger, a first-year social studies teacher, said in the more than 15 calls released late Wednesday. "Blood is everywhere. I do not see the gun. I have him down."

"I need help now. Shooter right here," she continued, breathing hard. "I tried to stop him before he shot himself."

"He shot, many are down," she later told the 911 operator. "I do not know how many are down."

Five students were shot on Oct. 24 by Jaylen Fryberg, a freshman who opened fire on the group as they sat at a cafeteria table. Four of the students died from their wounds; Fryberg shot and killed himself.

The 911 tapes reveal the chaos and fears in the immediate aftermath of the shooting, making Silberberger's response all the more admirable, said Joe Deedon, a law enforcement consultant and former tactical operator with the Jefferson County, Colorado, SWAT team.

"I can't speak highly enough about the professionalism and the great job she did to remain calm, cool and collected," Deedon told NBC News.

In one of the calls, a parent who said she guided students out of a side door from the cafeteria can be heard sobbing.

"He was just two tables away from my daughter," said the woman, Anne Haughian, who works in the school's food service department.

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In another, a boy, sounding out of breath, gave the operator a description of the shooter calling him Jaden and noting he was a freshman — and said he didn't know where he was then, a few minutes after the shooting.

"I don't know — I just ran out of the school. The door was right there, and I'm out of the school right now," he said, adding, "I'm OK. I'm in the car with two others."

Parents receiving text messages or phone calls from their children also figured in the 911 tapes.

"My daughter just texted me that there are shots fired at her high school," said one woman.

"We do have reports of activity at that location and the police are already — have been advised. Do you have any specific information?" an operator asked.

"Only that my daughter is not following lockdown directions and she and some other kids have run — run from their classroom," she said through tears. " … What advice can I give to her?"

"I don't know," the operator replied. "She needs to follow the lockdown instructions."

In another call, a man said, "I've got my son on a cellphone here saying he's at Pilchuck High School, saying that someone was shot in the lunch room."

"We've got the police and the fire department alerted to that, sir," the operator replied. "Do you know anything specific?"

"He was in the back. He was just really shaken up," he replied. "He doesn't know anything specific. I was just calling to let you know in case you didn't know."

The sole survivor of the shooting was Nate Hatch, 14, who was shot in the jaw but recovered. Last Friday, his relative Andrew Fryberg, 15, died from his wounds. Hatch was also related to Jaylen Fryberg.

Zoe Galasso, 14, died from a gunshot wound to the head during the rampage. Gia Soriano and Shaylee Chuckulnaskit, both 14, were also shot in the head and died days later.

The three boys and Shaylee were members of the American Indian Tulalip Tribes.

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