Bullying, therefore, is different from a single incident of teasing. It is, in fact, an abuse of power. Bullying also differs from play, and from the normal conflicts of childhood. When two children of approximately equal strength or power are engaged in a fight, it is not bullying. Thus, although all acts of bullying are aggressive, not all aggressive acts are bullying. Bullying can occur face to face or it can happen behind one's back, especially through cyberbullying. Cyberbullying is defined as willful and repeated harm inflicted through the medium of any electronic devices. Bullying can be short-term or it can last a long time. Bullying can be done by an individual or by a group.
At 11:19 ., 17-year-old Rachel Scott was having lunch with friend Richard Castaldo while sitting on the grass next to the west entrance of the school. Castaldo said he saw one of the boys throw a pipe bomb, which only partially detonated. Thinking the bomb was no more than a crude senior prank, Castaldo did not take it seriously. At that moment, a witness heard Eric Harris yell, "Go! Go!" The two gunmen pulled their guns from beneath their trench coats and began shooting at Castaldo and Scott.  Scott was hit four times and killed instantly. Castaldo was shot eight times in the chest, arm, and abdomen and paralyzed below the chest, falling into unconsciousness.  It is unknown who fired first; however, Harris was the one who shot and killed Scott, and Castaldo reported that Scott was hit before he was.