What height bridge or how many stories building do you have to jump from to be assured death?

[purplesky9]

Are scared of heights but need to find a new method.

 

[alland]

according to lostallhope.com it's 150 ft/46 m on land (10-15 stories) and 250 ft/76 m on water

 

[Alexandra_]

25 storey building and death is guaranteed

 

[darksouls]

I grew up in a 17-story house
anyone who jumped from the 17th floor died instantly
the floor was made of cobblestones