A french kid was metal deteching and set off part of a shell.

[Flying10uk]

Personally, I don't see the appeal of or interest in "metal detecting" at all. It would be investing to know what percentage of a "metal detector's " time is spent finding nothing or nothing of any value or interest in relation to actually finding something of interest and or of value. If a "metal detector" decides to "detect" over an area of ground that was once a battlefield I don't understand the surprise when unexploded ordinance is found. If that unexploded ordinance is hit hard with something like a shovel, one shouldn't be surprised if there is then a big bang.