Via Bayou Renaissance Man, here is the unusual story of a mid air collision between a Syrian Airlines Airbus 320, and a helicopter.   

It appears that the rotors of the helicopter struck the tail of the Airbus, chopping off the top.  The plane was able to return to the airport without a problem, but although there is no word of what happened to the helicopter, it almost certainly crashed.  An airliner like this can actually fly without a tail, albeit with difficulty, and there is a substantial piece left on this plane

How this accident happened would be good to know, as there is no reason at all that a helicopter should be flying anywhere near a commercial jetliner.

You can clearly see the chops made by the helicopter blades in the picture below.