In Shakespeare’s Romeo and Juliet, Mercutio is the first fatality of the street fight.
Mercutio confronts Tybalt in Verona after Tybalt seeks Romeo. Romeo refuses to fight Tybalt because he has secretly married Juliet and now considers Tybalt family. Mercutio, unaware of the marriage and irritated by Romeo’s refusal, accepts Tybalt’s challenge.
Romeo tries to intervene, but Mercutio is wounded under Romeo’s arm. Mercutio’s famous curse on both households follows, and he dies from the wound. Romeo then turns on Tybalt and kills him, causing the Prince to banish Romeo.
This sequence is a major turning point because it moves the play from comic romance toward irreversible tragedy. Mercutio is neither a Montague nor a Capulet; he is a kinsman and friend of Prince Escalus. His independent position lets him criticize both families, making his death a direct consequence of their feud even though he does not belong to either house.