What is the correct procedure if the property is empty by March 1st but I never got the keys back?

I think in VA if it's in question, I have to post notice that tenant must notify me in writing within 7 days if they intend to stay and if no response, I can assume it's abandoned and follow next procedures for turnover and security deposit. 

This is anything from screening tenants to moving out procedures.

when technology was nascent, norms and operating procedures totally different.

I checked with a few references, followed the company's procedures, and was granted the loan amount I requested.

States are very particular about the process and you're asking to have your case kicked out b/c of improper procedure on your part.

What are the procedures when this happens?

@Alan Charles, jurisdictions vary in their criteria and procedures for lowering property taxes.

Establish work and contact hours and emergency procedures outside those hours.  

If so, the short answer to your question is that a "free and clear" sale may not discharge certain liens (like an IRS lien) if the relevant parties fail to follow proper procedure.