If you want some detail...
A much more detailed write up:
https://blogs.msdn.microsoft.com/bharry/2016/02/05/vs-team-services-incidents-on-feb-3-4/
and
https://blogs.msdn.microsoft.com/bharry/2016/02/06/a-bit-more-on-the-feb-3-and-4-incidents/
The latter includes some rather low level details...