Pretty sure it was completely blocked long before 2008. My dad, uncle, then-wife and I crawled in (literally - to enter you had to drop between a large timber and the stone face of the portal to slide through a digout at the very apex of the portal) in the early 70's. Not sure I'd do that again either, but we were well equipped with hard hats, steel toed boots, multiple lights etc. We were able to reach well past the apex to a cave-in that probably wasn't that far from east portal. My mom and aunt waited nervously outside. They were NOT happy with us.
Scott