Thassarian, The Death Knight not working?

Guys today I was doing quest [Thassarian, The Death Knight] but he's "buried" under the Ziggurat and it is not possible to talk to him in any way. (Lordaeron)

Bugtracker links
https://www.warmane.com/bugtracker/report/36045
https://www.warmane.com/bugtracker/report/36039

Wait until server crash and all be ok. A lot of NPCs suffer from unability to reset position after combat lately.