What major incident happened to Melinda in Speak?

The major incident that happened to Melinda was that she was raped.  

That particular incident happens before the events of the book begin.  In the summer before beginning her freshman year of high school, Melinda went to a party for high school students attending Merryweather High School.  The party had students of all ages there, and alcohol was present as well.  Melinda had been drinking too, but she did not give sexual consent to...

The major incident that happened to Melinda was that she was raped.  

That particular incident happens before the events of the book begin.  In the summer before beginning her freshman year of high school, Melinda went to a party for high school students attending Merryweather High School.  The party had students of all ages there, and alcohol was present as well.  Melinda had been drinking too, but she did not give sexual consent to Andy Evans.  Andy Evans raped Melinda.  Melinda called the police from the party, and consequently all of the students at Merryweather High School treat her very poorly.  Over the course of the novel, Andy antagonizes Melinda to no end and tries to rape her a second time.  His actions are discovered, and people now realize what actually happened to Melinda at the party.