broken arrows:

To quote the website I found this on ;

"Since the 1950's , there have been  32 nuclear weapons accidents, known as "Broken arrows",

"To date , 6 nuclear weapons have been lost and never discovered"

The following link is to a map , basically,  including details of each.

I was pretty shocked when I found this. take a look and see what I mean.

map of  all the nuclear accidents since the 1950's