Minecraft wiki entry for Things_not_to_do, associated text: Normally, when the player sleeps, they wake up next to their bed if the space around it is not taken. It is important to leave a clear area around and above their bed. If there is not free space next to and/or above the player's bed, they may wake up inside a block and begin to suffocate. If this happens, remove the block quickly to avoid death by suffocation. If the player is killed, they cannot respawn at their bed; instead, they spawn instead at the world spawn, which can be far away from where the player was trying to sleep, along with a message saying, "Your home bed was missing or obstructed".