A statement that shows such utter disgust, contempt, hatred, and/or loathing for a fellow human being that you wish for them to expire in an extremely painful(and one would assume spectacular and tragic) way. This is usually precipitated by someone so violating what the wisher considers basic human decency, morals, or intelligence that little other recourse is avaliable.
15yo_girl: hay guyz, free paris!!
human_being1: Die in a fire.
Later in that same chatroom...
16yo_girl: AVRIL LAVRIGNE IS SO THE BEST ARTIST OF THE LAST 10 YEAR1111
human_being2: Stop yelling... and no, no shes not, her songs suck, for starters
16yo_girl: YEAH RIGHT11 HER SONG IMAGINE WAS SOOO DEEP111
human_being2: Die in a fire.