Ophelia's death in Shakespeare's play "Hamlet" is depicted as a drowning after she falls into a brook when a branch of a willow tree breaks while she is climbing and making a wreath of flowers. Queen Gertrude reports this event, describing Ophelia as mentally disturbed and floating in the water singing until she drowns. However, the exact nature of her death remains ambiguous—while Gertrude describes it as an accident, a church official at her funeral suggests Ophelia may have killed herself, which causes controversy and anger from her brother Laertes. This ambiguity is a central part of interpretations of Ophelia's death, which is sometimes seen as accidental drowning, sometimes as suicide driven by madness and despair, and occasionally even as suspected murder in some critical discussions.
In summary, Ophelia either died by accidental drowning or suicide due to her mental state, with the play leaving the particulars open to interpretation.