From what I can gather, the Philippines are mostly small islands at sea level, and since most of the people are poor, the houses are flimsy. And evidently this storm was so fierce that even if houses had been much more robust, they would have been leveled.
What is even sadder is that the islands get several typhoon (Pacific version of hurricane) a year- but even with that experience, they weren't able to prepare for this level of wind and rain.
The photos are terrible. The audio I heard on the radio last evening was much worse- according to the narrator, a little girl having her lacerations sutured, without anesthetic, because they didn't have any. That is horrifying.