Stunned by the horror that just transpired, a Christian pastor who is the father of one of the survivors of last Thursday's massacre in Oregon finally found the words to recall what his daughter vividly told him on what happened that day when evil in its purest form visited the school where his daughter was studying.

Speaking to the Los Angeles Times over the weekend, Randy Scroggins, 56, said his 18-year-old daughter Lacey owes her life to a boy, one of her classmates, who fell down on her after he was shot dead. His name was Treven Anspach, 20, one of the 10 people who died that day in one of the worst tragedies in Oregon's history.

Scroggins said that Thursday morning, her daughter Lacey, who was studying nursing at Umqua Community College, remembered looking up the clock in class to see what time it was: 10:27 a.m. A few minutes later, one of her classmates, Chris Harper-Mercer, 26, entered the classroom.

Suddenly a gunshot rang out. Lacey saw Harper-Mercer holding a pistol and he fired two or three rounds at the ceiling, telling everyone to get down.

At that point, Scroggins' daughter thought it was just an unannounced drill. She fell to the floor together with her classmates. But when she raised her head to see what was going on, she could not see her teacher anymore.

Then Lacey saw Harper-Mercer shoot someone. "And his body dropped to the ground, and I realised this is not a drill any longer," Scroggins recounted his daughter as saying.

Lying on the floor, she then heard Harper-Mercer say: "You, in the orange shirt. Stand up. What religion are you? Are you a Christian?"

When the student answered, Lacey told her father, "I heard, Daddy, I heard a pop, and then the thud of a body that just hit the ground."

Harper-Mercer asked the same question to other students and he shot them, too, Lacey said.

Then Lacey heard him telling someone to stand up and come over to him. That someone—Lacey was too scared to check who that someone was—did as told. "You're the lucky one. I want you to give this bag to whoever needs it. I've got a flash drive in it, and the rest of us, we will all be together in just a moment," Lacey clearly recalled Harper-Mercer saying this.

Then the gunman told another student that if she begged for her life, he would not shoot her. Lacey's classmate did as told and begged for her life. "Daddy, he shot her anyway," Lacey told her father.

"And then he told all of us to get to the centre of the room, so we all crawled as quickly as we could to the centre of the room. And then he walked over, Daddy, and he began to shoot."

Harper-Mercer shot randomly at the students cowering on the floor. A bullet hit Anspach who was beside Lacey. He fell onto Lacey, pinning her down.

"And then I heard him," Lacey told her father. "He stood over me and yelled, 'Get up! Get up!' But because of the weight of Treven's body on me, I felt frozen to the ground. And then he looked at the girl next to me who he had already shot, but she was still alive. And he said to her, 'Is she still alive?'"

Lacey knew the gunman was asking the wounded girl about her. She stayed motionless, pretending to be dead, with Anspach's blood gushing all over her.

The wounded girl answered: "I don't know." And then he said, "She must already be dead."

Harper-Mercer then stepped over Lacey and shot the next student beside her.

At that point, Lacey said she heard a woman telling the killer, "I'm sorry that you are going through this—I'm sorry that somebody has hurt you."

"I bet you are, but it's not good enough," Lacey recounted Harper-Mercer saying in reply. He then shot the woman.

Then a man entered the classroom and rushed at Harper-Mercer. But the killer shot him several times before he could grab him.

That man turned out to be Chris Mintz, a 30-year-old Iraq war veteran, who was in a nearby classroom, and who tried to stop Harper-Mercer from shooting more students.

Then moments later, Lacey heard a heavy burst of gunfire outside the classroom. The gunfire came from police officers who quickly responded to the emergency.

Lacey then heard Harper-Mercer say, "I'm done, you got me. I'm finished."

Then a loud shot rang out. Harper-Mercer shot himself to death.

When Lacey realised the killer was dead, she got up, pulled a scarf off her neck and used it as a tourniquet on one of the victims to ease the bleeding. She did the same to another classmate who also lay wounded.

The police then cleared the room and questioned her and the other survivors. Lacey then called her parents at home.

Scroggins said his wife answered the phone. She was numbed by shock, and could only utter his name, "Randy." Scroggins took the phone and heard his daughter wailing and crying. "Somebody has been shot!" she told her father.

When Scroggins picked up her daughter from school, she was still covered in Anspach's blood.

"We all believe with the last piece of effort that [Treven] had, that he moved on top of her on purpose," Scroggins said

"We know beyond a shadow of any doubt that his blood on my daughter convinced the shooter that she was dead," he said. "That young man, whose name is Treven Anspach ... saved our daughter's life."