HELP

One day, you are walking down the street. At the end of the street there is an abandoned house. You go into the house to explore around for a bit and notice stairs leading to the basement. As you slowly descend down the stairs, you start to smell something rotting. You slowly open the door and see a body lying in the middle of the room. You noticed that the room is made out of impenetrable metal and there is no window. You also notice that the door has no DOOR KNOB or handle, which makes it impossible to open from the inside. You walk up to the body and see a rock next to the body.

Q: Who is the Guy? What is the rock? How did he die?

H: 1. He is someone we've know since childhood.
2. A child is most likely to solve this riddle faster than adults.
3. I HOPE these hints are to easy.