Lethal jump height?

This is a really good article on why the guy that fell over 500 ft survived. Its all because of the physics of drag.

Moreno and his brother Edgar, 30, both worked for City Wide Cleaners. They were getting ready to wash windows on Dec. 7, 2007, when the cables for the scaffolding snapped. Neither wore a safety harness. Edgar died instantly when he fell off the platform and a fence severed his body. But Moreno managed to grab ahold of the 16-foot scaffolding platform--which proved crucial to his fate.

Following the training provided by his company, Moreno held fast to the platform--which increased the air drag on his falling body. And when Moreno hit the ground, the 1,250-pound scaffolding absorbed some of the shock of the 5.5-second fall, which could have reached a terminal velocity of 124mph.....
20 feet is the max a normal person can walk away from. A parkour expert can handle 25 maybe 30 feet tops.
as for fatal, Idk.