So I was playing my world a few hours ago and wanted to get off.  So I got off of my world.  I logged back in a few hours later and my WHOLE house and tons of chunks around where my base was is just gone.  It goes straight through bedrock.  I have been on and off of this world for a few days and it was fine.  The very last thing I remember doing before I logged off was placing my beehive I just found and making some candles.  I placed those candles down and lit them then exited the world.  It is probably not the reason but that might be a start.