My name for this ruin is for convenience only and not intended to be "official"; if the ruin had a name before I am not aware of it. It is in Fish C, on Cedar Mesa. This collapse happened sometime in the winter of 2003-2004; I visited this ruin with friends October 8, 2003 and it was intact; I rimwalked Fish January 14, 2004 but may not have looked at this ruin. This is the 'before' photo of this ruin. Note that all the walls are intact, and you can hopefully see how using the boulders on the right was the access route, now gone. Once you scrambled onto the boulders, you used Anasazi Steps and entered through the doorway in the 4 foot high wall on the far right. The right side of the bushes in front is where the crack used to be that split the boulders; also a very small bush is next to this crack, further up the boulder.
This is the 'after' view of this ruin taken 3/26/04. Compare this with the 'before' photo above. In this photo you can see how there's a gap between the ruin and the boulder on the far right; the stain on the slickrock is just below where the large 'access' block fell out. This block is now in a few thousand pieces on the ledges below. The sandstone block just to the right of the room with the hole, and slightly lower, used to be at the same level. Basically, then, there were 3 large sandstone blocks and the middle one slid out.
Here's a side view showing how the ruin is now at two levels.
The same view but from further away. The access route used to be in the foreground, using some Moki Steps, off of the block which slid off. The little protrusion photo right was close to the route.