We heard pretty much continuous shooting for the next minute or so, and I said, "Shouldn't we barricade the door," because we were sitting ducks with no way out inside that room if he opened the door. A couple more people floated the idea that "We need to barricade the door, NOW." But I was too scared to even move, much less move the teacher's desk.
Finally one of the guys in the front of the classroom was brave enough to get up and move the desk in front of the door to prevent outside entry. About twenty seconds later, the shooter rattled the doorknob trying to get in. When he couldn't get in he fired two shots through the door (single solid piece of wood) and left. We heard him go in to 206 (the room across the hall) and shoot the people in that room. If we hadn't put the barricade up when we did, I and all my classmates would be dead.
In other words, if it looks like you are doomed anyway, remember Todd Beamer's "Let's Roll". What have you got to lose? Who knows? You might just save yourself and others.