Ok guys what went wrong here 
…Answers on a post card to warsaw please 
Well, not sure as I drive a rigid!
But looks to me like the start of a classic “jack-knife manouvre” to turn round in RDC Quickly ! 
Naa Keep guessing.
Maybe their Delivering jumping beans
and not strapped them up properly
or delivering frogs ?
Maybe just saving on tyre wear whilst turning !!!
Or
Coupling up to a 45ft TL on a slight slope at an angle catching the fith wheel pin. ?
With frogs and jumping beans in the back ?
Deepinvet:
Ok guys what went wrong here
NOTHING - East Anglian tyre fitter takes invisibility & superman potion and lifts one side of trailer for weekly tyre inspection - EASY 
missed the pin. jacked it up, tug forward thinks it ok as the front of the 5th wheel is hitting the pin, done his lines done is legs.levelled it off, pulled away turned to the right and the trl has come of ,
Deepinvet:
Ok guys what went wrong here
Photo is a bit dark to make out properly.
The Poles are experts at crashing trucks into ditches,so I’ll go with that.
Afternoon Folks,
I’d have a guess that the wind has just caught it and it’s about to go over? 
Regards Smokinbarrels 
Heavy breaking perhaps ! Internal load moved during breaking. Combination drifted towards the edge of the road surface and nearside wheels tip over the edge causing the load to move even further.
Maybe … 
Use a name spot on!!! Well done 2 browny points for you
ha,ha, truck full of helium baloons floats away on m25…