CHINA (Reuters) - Theirs is a task perhaps few would envy.
These courageous volunteers are making sure China's latest glass-bottomed bridge is safe to be opened to the public.
At least one felt the need to shout "I love you mom" as she brought her sledgehammer crashing down.
They were attached to safety harnesses just in case but none of the volunteers managed to smash right through.
Just to underline how much the structure can take a 15-tonne vehicle was driven over the bridge as well.
At 300m above ground and 430m long, China's claiming this to be the highest and longest glass-bottomed bridge in the world.
These safety tests might also be intended to reassure the public after a similar bridge in the same province was closed last year because of a cracked panel.