The sequence of events is triggered by the killing of Polonius is:
1. Hamlet being exiled by Claudius,
2. Laertes returns to avenge his father, Polonius,
3. pirates attack Hamlet’s ship and he returns home,
4. Ophelia commits suicide.
In Shakespeare’s tragedy “Hamlet”, killing of Polonius triggers a series of events with are tied up at the end of tragedy. After Hamlet kills Polonius, thinking that he is Claudius, he is been sent to exile to be murdered. But, Hamlet knows of this plan and when the ship is being attacked by the pirates he survives and returns home. Meanwhile, Laertes comes home from Paris to avenge his father with intention of killing Hamlet in a duel. This series of events makes Ophelia go insane and she commits a suicide drowning in a river.