What if a Property Manager Vanishes?

[Jefferson Smith]

We found Michael Thompson of Evermark through Bigger Pockets. My partner talked to him extensively and liked him. We both met the guy. Michael did a reasonable job for some months, although he didn't have a good communication habits. In June, he went radio silent, not even completing accounting. Finally, he sent an email in July explaining he and his wife were moving to Southern Indiana, and that he would facilitate a transition to a new property manager.

But he has just ghosted. 

Has not replied to countless phone calls, text messages, and emails in nearly four weeks. We have identified a new property manager, but having no contact with him makes it hard to have a clean handoff (keys, security deposits, etc.) 

Anyone gone through a disappearing/nonresponsive/vanishing property manager before? (Anyone know Michael Thompson?) Any helpful tips? 

(Of course "get a reliable PM!" is the best advice, and we've had good luck in other micro-markets. And that good luck has meant we haven't had to deal with this before.)