By now, Harris and Klebold were inside the main hallway. Sanders and another student were down at the end of the hallway, where he gestured for students in the library to stay. They encountered Harris and Klebold, who were approaching from the corner of the north hallway. Sanders and the student turned and ran in the opposite direction. Harris and Klebold shot at them both, with Harris hitting Sanders twice in the back and neck, hitting his teeth on exit, but missing the student. The latter ran into a science classroom and warned everyone to hide. Klebold walked over towards Sanders, who had collapsed, and tossed a pipe bomb, then returned to Harris up the library hallway.