I believe this failure was caused by an earthquake.  The foundation appears to have given way along a clear fault line along the edge of the pilecaps. Structurally, the bridge appears to be intact. This indicates a clear foundation failure.   Notice the other buildings appear to be intact, they probably have been designed to withstand earthquakes.

Were these photographs taken in Korea?  Well, from some of the photographs, I can see the Japanese Kanji and Hiragana scripts. They certainly don't look like Korean script to me.