You're assuming a 90 degree turn. It doesn't take a 90 degree turn, however--they were probably still heading mostly down when they struck the wall. The wall

You're assuming a 90 degree turn. It doesn't take a 90 degree turn, however--they were probably still heading mostly down when they struck the wall. The wall (and the falling person) would absorb most of the impact. Not good for the faller but far better than keeping on going.