How about 14 stories plus a 15 foot garage level? I saw the aftermath of that while ago as freshman in college. A kid jumped at the most pedestrian trafficked corner of a dorm building and narrowly missed a coed walking to class. She felt his arm or leg brush past her as he fell the last few feet onto the concrete plaza surface. I was walking away from the point of impact about 10 feet from where he landed. It sounded to me like a trash bag full of water balloons had landed behind me. A sloshing sound, a bit of a thud and then a lot of coeds screaming. When I turned I could see it was a male on his back, his legs folded under him, arms out and blood starting to pour from his ears. Even with that grotesque scene - I walked closer to him, not really processing what it was for a few seconds.
So, long story short, 14+ stories gets the job done.