I'm back from Japan~ Wat a earthquake experienced

I had gone to Japan (Tokyo) for holidays from 07 Aug - 15 Aug. It was enjoyed trip for me though I went there alone. Unfortunately during my 2nd day trip, there's was a earthquake while I was inside dept store in Shinjuku. I had a shocked when I felt that the building suddendly tremor, at first I thought it was the subway train movement in the building underground. Then, a few seconds later.. the tremor is stronger and I saw the hanging lamp on the stationery dept. is swinging left and right. And the Japanese shoppers stop at their position and don't move, so I followed them. Hahaha..
After the dept. store announcement in both Japanese and English language then we knew is safe, so we continue our shopping.