Other reports say MLG door separated and hit the composite fairing. Looks dramatic but no structural damage from what I can see. Must have caused quite some noise in the cabin though...
Seems that ATSs are a bit fragile...
Many moons ago I did an evaluation of various makes/models and I was surprised to learn in the process that the ATR72 has the lowest structural weight per seat of ANY post-war airliner, which is a key selling point in high airport/ATC fee regions (which are MTOW driven).