(CNN) -- There was nothing about last Friday's biology department faculty meeting at the University of Alabama in Huntsville that portended the carnage that was to come, Professor Debra Moriarity told a reporter Wednesday.
"It was actually a really laid-back, mundane kind of faculty meeting," the biochemist told CNN affiliate WAAY about the 13 people seated around an oval table in Room 369 of the Shelby Center for Science and Technology. "Events coming up, scheduling classes, budgets. It was really actually one of the easiest faculty meetings we've had."
Among the participants was Amy Bishop, a Harvard-trained geneticist with whom Moriarity had developed a professional relationship nurtured by the fact that the two women worked with cell cultures. "Sometimes you borrow things back and forth from each other," she said. "We had talked about writing grant proposals together."
After about an hour, just before 4 p.m., Bishop -- who had recently been denied tenure -- ended the calm. "All of a sudden, she just stood up and shot," Moriarity said.
Moriarity reacted quickly, dropping onto her hands and knees on the gray carpet. "Just dropped to the floor and crawled under the table and crawled towards Amy," said Moriarity, who was focused on one thing.
"I mean, you're crawling under a table, you see the legs of a person who's shooting above the table. I grabbed her leg and, I don't know what I was thinking. I wasn't thinking anything. I was just thinking: 'Grab her!'
"And she sidestepped me. I mean, she pulled her leg free and I was in the doorway then with my back kind of to her. And I think she tried to shoot at me then, but that's when I started yelling at her, 'Amy, Amy, think about my grandson, think about my daughter! This is me! I've helped you before; I'll help you again! Don't do this Amy! Don't do this!'"
Bishop then stepped out into the hall, pointed the gun at Moriarity and pulled the trigger, the biologist said. "It clicked, and it clicked again, and I crawled right back in the room and shut the door and she was left out in the hall."
The survivors burst into action. One person locked the wooden door, another shoved a table against it, others moved a refrigerator into place to further block the door, another called 911, others moved to help the six people who had been shot, Moriarity said.
Three people died; three others were wounded. Two of them remained hospitalized Wednesday in critical condition, according to a spokeswoman for Huntsville Hospital. The third has been released.
Moriarity, who joined the school's faculty in 1984, said the casualties have not affected her plans to remain at the school. And she rejected any suggestion that her role in getting Bishop out of the room was heroic.
"She followed me out in the hall and then the gun jammed and I could get back in the room," Moriarity said. "That's not being a hero. That's just God looks out for you."
She said she had had little time to think. "From the beginning until we finally got things barricaded, it couldn't have been more than 20 seconds," she said.
Moriarity further rejected suggestions that anything could have been done to protect the victims. "There was no way to ever anticipate this," she said. "And there was nothing that could ever have been done to stop her. It all happened too fast."
And she worried that any attempt to tighten security could have negative consequences. "There is evil in the world; it is unfortunate that good people are hurt by that. But a university is a place of free thought and freedom to explore ideas and to search out new knowledge and you don't want to put anything in place that dampens that."
Moriarity returned to her office on Wednesday and said she plans to resume teaching next week. She predicted that, with the help of anti-anxiety medication, she would be able to sleep Wednesday night.
"I've been talking to family and friends and just getting their support helps you deal with it," she said. "I think right now most of us want to get back there and get things going, make plans for who is going to cover classes."
A memorial service to honor the lives of the dead -- faculty members Maria Davis, Adriel Johnson and Gopi Podila -- is to be held Friday.