Incidents:Rockfall in Deimos

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Rockfall in Deimos
Date 2021/01/30
Location Deimos_Canyon
Severity Fatality
Canyoneering-related Yes
SAR involvement Yes
Navigation problem No
Environmental problem Yes
Communication problem No
Planning problem No
Skills problem No
Body movement problem No
Rigging problem No
Rappel problem No
Insufficient gear No
Gear failure No


"Justin Ibershoff (38) of Los Angeles, was descending a technical route down Deimos Canyon with six friends. The group was very experienced, and most members of the party had descended this canyon several times before. The incident occurred while Mr. Ibershoff was descending a steep, rocky slope to the top of the third rappel anchor. He apparently stepped on a rock that moved, triggering a rockslide that swept him past two companions and over the edge of the 95-foot-tall dry fall.

The group used an emergency locator beacon to call for assistance. The group’s ability to send more detailed information via texts through the emergency beacon aided rescuers. After assessing Mr. Ibershoff’s condition, the group continued down the canyon due to continuing active rock fall.

Inyo County search-and-rescue (SAR) and Death Valley park rangers were assisted by helicopters from California Highway Patrol (CHP) and Naval Air Weapons Station China Lake. Crew from the Navy’s VX-31 helicopter were able to reach Mr. Ibershoff a few hours after the accident and establish that he had passed away. At that point, the incident response transitioned into a body recovery.

Inyo County SAR team members and CHP’s H-82 helicopter from Apple Valley recovered Mr. Ibershoff’s body the next day.

Conditions in that area of the canyon remain unstable and canyoneers are advised to avoid the upper section of Deimos Canyon."
~Abby Wines, Death Valley NP news release


What happened was a rockslide inside the room with the false floor, but it was not a result of the false floor. It was the bed of rocks that accumulates in there between the canyon walls. Yes, it is all on top of a false floor, but the floor is not what failed, and the same rockpile could exist regardless of the floor type.

That this particular type of failure would occur was not predicted. Because of the false floor, there was always this nightmarish fear of the chockstone floor structure possibly collapsing, but that is not at all what happened. The other concern has always been that one or a few of the rocks from the room would tumble towards the rappel and be a hazard to anyone on rappel or standing at the bottom of the rappel. That is also not what happened.

What happened was a rockslide of horrifying proportion, where a deep layer of rocks on the floor suddenly gave way and slid down the slope towards and over the brink of the rappel.

I also want to make it clear that there was nothing unusual or particularly hazardous looking about the locations where any of the three of us were actually standing. None of us were on a steep slope or standing at the edge of one. We were on a gradually sloping floor of rocks, the same kind of thing we stand on all the time in other places. And, importantly, not any different in appearance from the floor in that same room the other five times I have been in it.

What we didn’t expect, and had no reasonable way to expect, was that a failure that occurred several feet away, closer to the brink of the drop, would cause the entire mass behind it to slide.