>> i froze. i just stood there not realizing what was going on. i'm looking at everybody dropped down on the floor. >> reporter: but then she realized what was happening. >> the moment i looked over at my friend and she was slumped over. her eyes were closed and there was blood just gushing out of her neck. that's when it kicked in for me and i was like, oh, this is real. like, i have to run. and that's literally all i thought of. and he went in one direction and i just went in the other and i was just praying the entire time. i was running, hoping he's not behind me. >> reporter: briana says ...