He would do anything to protect Naruto, who was just injured in battle because Kakashi was late, now Kakashi feels guilty. He found Naruto on the ground, in battle, injured. He held the boy, who was passed out, on his back with the boy's head on his shoulder. They were in the rain and he was looking for the closest place that could be a temporary shelter until the upcoming storm passed. A house was much closer than the leaf village, in an isolated place, so He decided that would be a good place. He thought the house was abandoned, so he was going to break in. But he realized there was someone living inside that house, so he just knocked on the door. Hoping to still be able to get into the house.