Incident:Rope cut in Terepocki Creek 2025/07/19
| Incident:Rope cut in Terepocki Creek 2025/07/19 | |
|---|---|
| Date | 2025/07/19 |
| Location | Terepocki Creek |
| Severity | Injury |
| Canyoneering-related | Yes
|
| SAR involvement | No
|
| Navigation problem | No
|
| Swift water problem | No
|
| Environmental problem | No
|
| Communication problem | No
|
| Planning problem | No
|
| Skills problem | Yes
|
| Body movement problem | No
|
| Rigging problem | No
|
| Rappel problem | Yes
|
| Insufficient gear | No
|
| Gear failure | Yes
|
Summary[edit]
On July 19th, during a descent of Teropocki Canyon, an incident occurred at the first rappel, where the rope snapped mid line as the rappeler was 15 feet above the bottom of the rappel. This this incident how compounding huristic errors can cause a near fatal incident.
Things to note: this was a relatively experienced group, with two professionally trained individuals and one seasoned adventurer, but novice canyoner.
The first person in the group rappelled down next to the waterfall without issue, following the direction of the anchor. The second person (least experienced) opted for a line closer to the main water flow, after asking the pitch lead if it was okay, to which the response was to try it out. The rope was repositioned to follow the watercourse and was set over a horn of rock, which appeared to be stable with a non-sharp, obtuse edge, but with a significant deviation.
After pausing on a ledge to take a photo, the second rappeller proceeded with two long bounds. After the first bounce, the rope popped over the horn, causing the rappeler to swing over, likely causing the initial core shot. After the second bounce, the rope severed near the top corner, causing a fall of approximately 15 feet into the shallow pool below. The pitch leader was creeping the rope at the top to try and avoid too much abrasion, but could not see any of the movement going on from the top.
The individual was largely unharmed but sustained a laceration to the knee, likely due to an existing tear in their wetsuit that exposed the skin to sharp rock.
Once at the bottom, first aid was administered to clean, bandage, and wrap the injury. It was determined that the injury sustained was not debiliating, and the group then descided to continue the descent and completed the canyon safely.
During the incident, multiple cognitive and heuristic errors contributed to a failure in safety decision-making. The trip leader exhibited signs of expert halo bias, assuming a participant’s technical competency based on previous experience together rather than verified skills. Simultaneously, the rappeler displayed recreational and familiarity heuristics, favoring an enjoyable rappel line and technique over a conservative and terrain-appropriate choice.
Communication missteps compounded the issue: the rappeler sought validation on their line choice, and the leader’s ambiguous “try it and see” was misinterpreted as full approval—an example of authority bias and confirmation bias at play. These combined factors led to a poor rope managment orientation, ultimately resulting in rope failure while weighted.
This could have been prevented with more conversation about how to choose the line with more caution, and static rappeling techniques that can avoid shock loads to the system.
This could have ended a lot worse, and everyone was lucky it went the way it did.
Trip Report: Teropocki Canyon – July 19th Incident[edit]
On July 19th, during a descent of Teropocki Canyon, an incident occurred at the first rappel in which the rope severed while under load, resulting in a fall of approximately 15 feet into a shallow pool. Fortunately, the rappeler sustained only a minor laceration to the knee, and the group was able to administer first aid and continue the descent safely. However, the event underscores how compounding heuristic and communication errors can escalate into a near-miss scenario.
The group consisted of three individuals, all seasoned canyoners. The first team member descended without issue, following the anchor direction on a dry line beside the waterfall. The second member chose a rappel line closer to the main water flow.
The rope was repositioned to accommodate this line and was placed over a horn of rock. At the time, the edge appeared safe, with an obtuse, non-sharp profile, but involved a significant deviation under tension. While descending, the rappeler paused to take a photo on a mid-rappel ledge and then continued with two dynamic bounds. After the first, the rope shifted position, likely causing a core shot as it moved across the rock horn. After the second, the rope severed near the top deviation point, resulting in the fall.
The pitch lead was creeping rope from the top and attempting to mitigate abrasion, but had no visual on the rappeler’s actions due to terrain. First aid was administered at the bottom for a minor knee laceration—believed to be exacerbated by a pre-existing tear in the wetsuit exposing skin to sharp rock.
Analysis & Contributing Factors[edit]
This incident highlights a combination of heuristic traps, communication breakdowns, and terrain-specific rigging risks.
Key contributing factors include:
- Expert halo bias: Competency was assumed based on prior experience, without verifying canyon-specific technical proficiency for the chosen rappel line.
- Recreational/familiarity heuristic: The rappeler favored a more engaging, water-focused line without fully assessing the risks associated with deviation angles or rope-abrasion potential.
- Rope path and deviation risk: The chosen rope line introduced a significant deviation over a horn of rock, which under dynamic load caused shifting, abrasion, and ultimately rope failure.
Lessons Learned
Pre-rappel briefings should include clear expectations for line selection, especially in areas where rope movement or abrasion potential is high. Varying levels of training and technical depth—even among experienced adventurers—can lead to mismatched assumptions.
Static rappel techniques and careful, deliberate descent should be prioritized in deviation-prone terrain to reduce shock-loading and rope shift.
Visual communication limitations from the top should be accounted for. When the rappeler is out of sight, extra emphasis should be placed on pre-rappel planning and clarity around risk boundaries.
This incident was a serious near miss that could have had more severe consequences. The group responded quickly and appropriately, and the rappeler was fortunate to escape with only a minor injury. Moving forward, this event reinforces the importance of verifying skill alignment, improving clarity in communication, and making deliberate, terrain-informed decisions to mitigate avoidable risk. It serves as a strong learning opportunity and a reminder of the risks we take in the sport we all love.
Accounts[edit]
FB post: https://www.facebook.com/groups/485642308115596/posts/24660920950161061/