Rock fall @ Cascade Crag, Boulder Canyon 5/21/17?

Read this alarming comment on the Cascade Crag main page today:

"Does anyone know about any massive rock fall that took place here on Sunday, May 21, 2017? A number of other climbers and I at the upper and lower Bihedral areas were alerted by a bloodcurling "ROCK!" scream (which sounded more like someone falling from the rock) and witnessed what must have been school-bus-sized (or larger) chunks of rock fall from the top of the buttress. Hopefully no one was injured! If this is the right crag, then climbers should take note that some routes and the area may be significantly altered."

Anyone have more info?

Wow! Must've just missed this.

I was across at lower tier of Bihedral, moved from Cascade couple hours before. I saw the couple that kicked off the rocks, they were all the way on top of the crag. When I saw them there, I thought it strange, because it looked to me that all of the routes have rap rings or mussy hooks. Anyway, my buddy was about to start climbing when we heard it, bloodcurdling Rock! scream. It sounded so primal. I looked back, and for a second it looked like a person falling, few big sized rocks were tumbling down. All the parties under were luckily on the upper end of the crag, the rockfall came down through the middle. Yeah, we could have been there if we hadn't changed our mind and moved to Bihedral area. I hope the girl that kicked off rocks learned her lesson. 

Rich Farnham wrote:

school-bus-sized (or larger) chunks of rock fall from the top of the buttress

Holy... I think I need clean pants just reading that. Glad no one was hurt!

There's a big difference here between OP' quote and Fehim. There's no way someone can kick a school bus sized rock off a cliff so whats actually going on?

She must have strong legs.

It wasn't a school bus sized, more like a person size which would make them what, 200-400lb heavy. Still no joke if you're under 

Tylerpratt wrote:

There's a big difference here between OP' quote and Fehim. There's no way someone can kick a school bus sized rock off a cliff so whats actually going on?

You can kick off multi-thousand pound flakes with only body weight for sure.

Was out and about a lot last weekend and there were plenty of rocks that fell off by themselves in the road.  

Fehim Hasecic wrote:

I saw the couple that kicked off the rocks, they were all the way on top of the crag... 

That's terrifying.  Glad everyone was ok.  Pretty rare that the base of that crag wasn't packed full of people on a weekend!  Could've been pretty ugly!

Anyone been to Cascade to inspect from the road? My friends who saw the rock fall named a different crag: Witches Tower.

Fehim Hasecic wrote:

It wasn't a school bus sized, more like a person size which would make them what, 200-400lb heavy. Still no joke if you're under 

The specific gravity of Granite is about 2.7.  So a human sized block (by volume) would weigh about 500lbs.
A 3*3*6' block (2 cubic yards) would weigh about 9000lbs.

So yeah, anything big enough to see from across the road is really really frightening to think about.

And yeah, it is not that hard to trundle an unstable block of that size.

It's definitely the season.  Went up to Caribou via the canyon Sunday and the road cuts had come down in 3 separate places when you were about at the res. 

Tony B wrote:

The specific gravity of Granite is about 2.7.  So a human sized block (by volume) would weigh about 500lbs.
A 3*3*6' block (2 cubic yards) would weigh about 4400lbs.

So yeah, anything big enough to see from across the road is really really frightening to think about.

And yeah, it is not that hard to trundle an unstable block of that size.

isn't granite about 175 pcf? that would put the block around 9450 or so wouldn't it?

slim wrote:

isn't granite about 175 pcf? that would put the block around 9450 or so wouldn't it?

Yeah.. the specific gravity I looked up is correct, but the density number I picked up was for gravel (lots of air).  You are correct!  (post corrected)