Ollie Onion described very well (probably better than I can) what I believe may have happened. There are some things we know for sure and some things which are less certain but plausible. What is undisputed is that they made a first approach intercepting way above the glide slope. The ensuing approach was unstable and at some point they went around. For some reason the engines (but apparently nothing else) made contact with the runway. It seems both engines were damaged before the aircraft then climbed away and made another approach resulting in it crashing with the gear down into a built up area some way short of the runway. Whether the gear was down and selected up prior to making contact with the runway or they never lowered the gear is not yet known. Why the aircraft did not initially climb away as expected on the missed approach is also net yet certain. Some of us with experience on the aircraft have referred to previous events where TOGA was not properly engaged. It is quite different to Boeing TOGA triggers and whilst it seems incredible that something as easy as firewalling the thrust levers could be got wrong, people continue to do so. As for the gear we will no doubt find out soon enough, but either way it doesn't change much, a bit like choosing between plague and cholera as we say in Germany, both are just as bad.