was real, but she surprised herself with how she reacted. >> what i did is not right, but, you know, sometimes you never know what you're going to do, how you're going to act. >> today she still works long hours at the store and is thankful that lucky ax was close by. it's the early morning hours of june 3rd, 1999, at this albertson's supermarket in las vegas. 23-year-old zack emmenneger is working the graveyard shift. >> it's a typical day. i mean nothing was out of the ordinary at all. at all. >> at 5:15 a.m., a security camera is trained on the east entrance of the store. an employee can be seen pushing a row of carts away. seconds later, a man named zane floyd strides through the door with a shotgun. he shoots the worker point blank in the back. 40-year-old thomas darnell is killed instantly. floyd roams the store in search of more victims.