Staircase Fall, the site of today's rock Fall - From Wikipedia
A rock slide struck cabins near the Curry Village ampitheater this morning.
There are some unconfirmed reports of minor injuries. Update - there were some injuries, the worst being a boy who had a head laceration that required stitches.
Another slide happened there yesterday and Yosemite Blog reports that the perimeter around the cabins was closed. Hopefully it remained closed until this AM. This slide appears to be much larger than yesterday's. Update: this slide was reported to be from a 1800 cubic yards slab, about the size of 12 garbage trucks.
We'll update this story with more as it comes in.
Update 2: Here are some photos from the AP.