First off I wouldn't say landslide because if it was a landslide in more than likely would have cracked the concrete on the floor that the people are standing on and there would be more of a mess than what is show in the picture. Next I wouldn't say tsunami depending on how frequent this disaster was, if it was a tsunami more than likely most of that rubbish would have been soaked with water in other things that were in the water as well and I wouldn't say flood either because once again nothing is soaked with water with in that picture not even the concrete that the people are standing on so I say that the most reasonable answer would be earthquake due to them being know for destroying buildings alot.
Your heart is racing because you're breathing hard and trying to catch your breath which makes your lungs expand and contract quickly. By sweating your body is trying to reach homeostasis by cooling you off. Just a simple explanation.
