Pilate was surprised to hear that he was already dead. Summoning the centurion, he asked him if Jesus had already died. When he learned from the centurion that it was so, he gave the body to Joseph.
Jesus didn’t last too long on the cross. Most times criminals would hang for a day or more. Jesus lasted just six hours. Crucifixion kills by two means: blood loss and suffocation. As the condemned hangs on the cross with his arms out to the sides, it restricts the amount of air that can get into the lungs. As time goes by, the lungs begin to fill with fluid and it gets harder and harder to get enough oxygen. For a while, you could push yourself up with your feet to get a little more air, but the nail in your feet makes that more and more difficult.
This day, the two criminals crucified with Jesus had to have their legs broken so they could no longer push up. When they came to Jesus, he was already dead. He died quickly of his own will. Jesus gave up his spirit. Death did not drag him down; he willingly gave up his spirit.