The death of Uriah is recorded in the Bible in 2 Samuel 11. Uriah was a loyal soldier in King David's army, and David had an affair with Uriah's wife, Bathsheba. When Bathsheba became pregnant, David tried to cover up his sin by bringing Uriah back from the front lines of battle and encouraging him to go home and spend time with his wife. But Uriah, a committed soldier, refused to enjoy the comforts of home while his comrades were still fighting.
Desperate to cover up his adultery and the impending scandal, David ordered his general, Joab, to put Uriah in a position where he would be killed in battle. Joab carried out David's orders, and Uriah died in battle.
So, the person responsible for the death of Uriah was King David, who gave the orders to have Uriah placed in harm's way, and his general, Joab, who carried out those orders.