Why is this interesting? Well, first lets note that we should ignore the red colour on the face of the scarp - this is a mantle of tropical soil that have come down from the crown of the slide (you can see the red soil at the very top of the landslide - this is of course typical of a tropical area). More important is the structure behind the mantle of soil debris. Here it is clear that the rocks are horizontally-bedded (or at least nearly so). Such a large failure in horizontally-bedded rocks is certainly not unprecedented, but is slightly surprising. The debris is very coarse-grained and has travelled quite a long way, which is also interesting.
Often, failures like this are associated with some process that has caused undercutting of the toe - for example wave erosion. Clearly there are no waves here - I wonder if there had been any activity to quarry stone from the slope, perhaps as a building material?
I am reminded of the Manshiet Nasser landslide in Cairo a year ago:
In that case the key cause was probably quarrying at the foot of the slope.
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