Examples of how taking a risk hasn't paid of in mankind's history?

Question

Any examples please, eg. vaccines that weren't properly tested, planes not built well etc...

Answer 1

Thalidomide was thought to be the big break through for morning sickness in pregnancy, sadly it wasn't and left so many babies without limbs.

Answer 2

Delorean's Car, also the Edsel (both flops).

We are now learning that the Titanic was not made well, and it was the first of kind (along with a sister ship).  

Answer 3

thalydomide,agent orange, the spruce goose..operation barbarossa (the n**i invasion of russia) .

Answer 4

Titanic - risking increasing the speed to arrive sooner and ended up crashing into an iceberg

The Somme - Britain bombed the German trenches and assumed they had all been killed. The soldiers walked across no-mans land and were mowed down as the plan hadn't worked.

There's a lot of political and economical policies you could look at. Keynesianism - pouring money into the economy to get it going again etc. During the Great Depression, you could say Hoover risked not doing anything and it didn't pay off because the economy didn't recover naturally and he lost the election.

The policy of Appeasement (pre-WW2, the idea that giving in to Hitler's demands would satisfy him and he would stop) eg. not Reacting to the Anschluss etc. That didn't work at all.