I am very sorry to hear about this unfortunate incident. I hope @steemitblog and the Steemit Inc., Engineers can assist him.
I assume they have contacted the holder of his recovery account an activated the recovery procedure?

This may allow him to regain control of his account, especially if he didn't reveal his master key.

This account recovery procedure will possibly allow him to regain control of his account, and save his Steem, as it will take four weeks to completely power down his Steem.

I will research the recovery account and place additional links to the information here.
@shortsegments