Analysis of the Durrand Glacier Avalanche Accident

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Durrand Avalanche Report page 19 2. From the guide’s position, it would not have been possible for him to see the avalanche crown, or look down the couloir and see the slide path, or even the debris field where his clients were buried. This may explain why, according to at least one participant, there was some initial disbelief and hesitation by the guide when he was first told that an avalanche had occurred, and that people were buried. Once the full impact of the situation was recognized, the eight survivors above the avalanche scarp removed their climbing skins, made their way over the scarp, and then down the 36-37°, 310 metre long, smooth and icy bed surface of the avalanche to where the victims were buried. R. The avalanche rescue 1. After the avalanche occurred, Ruedi Beglinger radioed the Durrand Chalet, and asked for all available assistance. But personnel in the lodge were too far away to offer any direct assistance, so all they could do was call Selkirk Mountain Helicopters (SMH), who initiated the main outside rescue response. There is an incomplete record of the response, but the following times were reconstructed from various sources: 10:45 am: The fatal avalanche occurs (there is no independent corroboration of the exact time). Ruedi Beglinger radios the Durrand Chalet and asks for all available help. 10:50 am: Durrand Chalet personnel radio Selkirk Mountain Helicopters, who initiate the main outside rescue response. 11:05: Selkirk Tangiers Heli-Skiing (STHS) personnel overhear radio conversations related to the accident, and volunteer to send three of their guides in to help. 11:20: Revelstoke RCMP are notified that an avalanche has occurred in the Durrand Glacier area. It is not clear why it took about 35 minutes to alert the police. 11:23: The three STHS guides are picked up by Selkirk Mountain Helicopters and flown to the accident area. However, due to bad weather, they cannot land at the accident site until 11:41, just in time to help dig out the last victim. 11:38: Thirteen Provincial Emergency Program personnel in Golden are mobilized to help in the rescue effort. It is not clear if they were flown to the accident site. 11:41: The first helicopter arrives at the accident scene with three outside rescuers (the STHS guides). 11:45: The last victim is pulled from the avalanche debris. S. Probability of death with burial time and burial depth 1. Statistically, the probability of finding buried avalanche victims alive diminishes rapidly with time. A recent compilation is summarized in the graph below and indicates that less than 50% of buried victims are pulled out alive after about 30 minutes. Note that many (by some estimates up to 35%) totally buried victims die due to trauma, the rest through asphyxiation that occurs as an ice mask forms around their face. These statistics emphasize the urgent need for speed, and an efficient rescue operation, when an avalanche accident occurs. Copyright: no part of this report may be reproduced without the written permission of the author.
Durrand Avalanche Report page 20 100% 80% Survivors 60% 50% 40% 20% n = 638 0 0 20 40 60 80 100 120 140 160 180 200 220 240 m Burial Time (minutes) Fig. 19: Survival rate versus time before rescue (minutes) for buried avalanche victims. 2. In this case, the data suggests that, given the deep burial of the victims, and the delay in getting outside rescuers to the site, the totally buried victims had a very low probability of survival. This may explain why all but one of the fully buried victims died. 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 0.0-0.4 m 0.5-0.9 m 1.0-1.4 m 1.5-1.9 m 2.0 m Fig. 20: Survival rate versus depth of burial (n=252; source: CAA). Copyright: no part of this report may be reproduced without the written permission of the author.
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Analysis of the Durrand Glacier Avalanche Accident

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