Hamlet and Laertes are fencing when they both wound eachother with the poison. "Laertes wounds Hamlet. Then( in scuffling they change rapier,) and Hamlet wounds Laertes.(5.2.)"
The queen drank the poison that was for Hamlet so she dies from it. "No, no the drink, the drink! O, my dear Hamlet! I am poisoned.(5.2.340-341)"
Hamlet kills the King by stabbing him with the sword and then making him swallow it. "Here, thou incestuous,(murd'rous), damned Dane, Drink off this poison. Is thy union here? follow my mother.(5.2.356-358)"