Windsceen wipers 2002 4.4 V8 L322

[NewDragon81]

Driving home from work in the p*ssing rain and surprise! Driver side windscreen wiper ceases to work. Passenger side collides and lifts clear of the screen and waggles back and forth uselessly.
Anyone had this before and able to advise as to what is most likely candidate for breakage?

 

[Datatek]

Driving home from work in the p*ssing rain and surprise! Driver side windscreen wiper ceases to work. Passenger side collides and lifts clear of the screen and waggles back and forth uselessly.
Anyone had this before and able to advise as to what is most likely candidate for breakage?

Wiper arm loose on the shaft or the wiper arm gearbox failed.