This website shows some pictures of the accident including the concrete block in front of the threshold that ripped off the undercarriage:
https://www.meinbezirk.at/salzkammergut/c-lokales/bruchlandung-der-legendaeren-antonov2-am-flugfeld-laakirchen_a3585414#gallery=default&pid=20718936
NB: The website of the airfield gives a landing distance of 550m for runway 08 which is plenty for that kind of aeroplane. No need at all to land before the piano keys.
NNB: The approach chart (this link is from the airfield website:
http://www.fliegerclub-traunsee.at/w...u-Jeppesen.pdf) explicitely warns of "I
n front of both RWYs marked steep slopes".