One more video:
https://www.facebook.com/video.php?v=1053519784674205
Looks to me like left Engine failed but didn't feather, crew let it get too slow and went below VMCA.....all over red rover.....
They were going to crash well before that wing drop/Vmca roll at the very last few seconds. IMO it was probably a secondary/wing drop stall, possibly the pilots pulled just a bit too much after they realised they might hit the motorway.
High sink rate + pitch relatively high +wings level = partially/fully stalled
Given that the ATRs should have enough performance to not fall like a rock after an OEI scenario with wings level (with or without autofeather) this is leading me to believe it's a double engine failure and I agree with pattern_is_full that the pilots might be trying to pull off a 'Sullenberger' on the river.