It is not in the English news sites yet but the internet line shared by VNPT, Viettel and FPT was damaged recently outside of Vung Tau somewhere in the ocean. I found out yesterday from my friend at VNPT when I complained about the terrible bandwidth from Vietnam to the US.
Nobody seems to know when the line was actually damaged but I think it happened last Saturday morning when we had the small earthquake.
The line is supposed to be repaired sometime next week but nobody knows when for sure. I heard that they were still trying to locate where the line was actually damaged.
Took nearly 5 days but finally the news is reporting about the cable breakage in English: