We (a bunch of mostly grad students mostly in the 4th year) went on a hike to a waterfall on Sunday. It was on the North peninsula near Stinson Beach. (I'm familiar with Stinson Beach since that's the landing zone for hang gliders launching from Mt. Tamalpais.)
It was a pleasant hike with greenery and little lakes/ponds with no streams in or out. I presume they're groundwater-fed. At the end, we had to climb down this steep crumbling rock face.
( cut for large image )Alex, who broke his arm hang gliding a few months ago, also attempted the climb. Here you can see him:

Seconds after I took that picture, the rocks under his feet slipped, putting weight on his left arm, which was apparently not fully healed, and fractured it again. Amazingly, he didn't do any of the things I'd have done (e.g. screamed, yelled for help), and simply said he'd broken it.
Unfortunately, this accident occurred at the very farthest point of the hike--it was another 4 miles or so back to the car, and then an hour and a half back to Berkeley. Alex held up amazingly well. When he wasn't thinking of all the hassle this accident would cause him, he was downright cheerful, and he scarcely seemed to feel any pain. He set a comfortably brisk pace back to the car, without any of the whining I'd have done. Zach made a very nice makeshift sling out of Jessica's long-sleeved shirt (I wanted to do something of the sort, but I had no idea how).
Alex went to the ER, where they took X-rays and put a splint on his arm. Today he's going to go see the same doctors who fixed his arm after the hang-gliding accident.
This all seems rather matter-of-fact, but that's more or less how it played out. Alex stated what happened, Louis helped him negotiate up to stable footing, we arranged a sling, and walked back.