The nose looks high on the straight part of the flight, so speed low, and the wing drop may be involuntary as it stalls, rather than turning deliberately at that moment, and then there isn't enough height margin to recover.
It seems that the approach to that runway (12) at the new airport involves flying over the old airport, on a slightly doglegged approach using a navigation aid on the old airport.
However, it is reported that this aircraft had asked for a change from 30 to 12, and it may have been doing a circuit on the north side, a base leg roughly in line with the old airport, then a left turn would have been coming up.
(Elsewhere, some people have checked landmarks in that video, such as a stadium, against maps satellite view)
One or two people speculated they may have been trying to land at the old airport by mistake, and realised a bit late. This seems unlikely, given the height at that point, and they'd asked to change runways on the new airport, and had already arrived there a couple of times earlier in the day
A dreadful event, and horrifically enhanced for the people who were seeing the video live
The flight data recorder (sometimes nicknamed black box) and cockpit voice recorder will help the investigators.