The standoff continues.(THE GOODNESS OF AMERICA)(Virginia Tech Shootings)

Zach Petkewicz is a 21-year-old senior math major at Virginia Tech whose story is similar to that told by Derek O'Dell. On the fateful morning, he was in a classroom inside Virginia Tech's Norris Hall when he heard sounds from outside the room that he did not recognize as gunshots.

"The girls in my class peeked out in the hall and saw a gunner come out of a classroom with his gun pointed down," Petkewicz told CNN.

"They immediately slammed the door shut, told us [what was happening outside], everybody kind of went into a frenzy, a panic. I hid behind the podium and then just kind of looked up at the door. Like, there's nothing stopping this guy from just coming in. And so I said, 'We need to barricade this door.'"

Zach and two other students shoved a long table against the door and held it in place while standing behind the cinder block walls on either side of the doorway. They heard shots coming from the hallway.

"He came to our door, tried the handle and couldn't get in because we were pushing up against it--and tried to force his way in ...