Here the runners had to walk the line along a metal pipe. It sounds manageable but the whole construction shook when more than one person tried to cross. If you fell down, there was a detour around some poles in the water.
Apparently the main problem was the water under the construction. More than one ankle and one knee was twisted. In fact, I think we were there when a woman broke her ankle.
In the image I caught a guy who got the wind blown out of him as he fell across the metal pipe.