The Mt. Tomuraushi Incident

Posted on Dec 6, 2018
Posted on Dec 6, 2018
6 7
In July 2009, the hiking world in Japan was rocked by one of the worst human-casualty disasters in modern history. Eight elderly members of a 15-strong organized hiking tour died of hypothermia while attempting a hike across the northern reaches of the Daisetsuzan mountain range in central Hokkaido. Known domestically as the Tomuraushi-yama incident (トムラウシ遭難事故), the disaster highlighted the risks hikers face in Hokkaido, even at the height of the summer hiking season. In this post, Rick Siddle summarizes Haneda Osamu's (2012) published account of the disaster.

Last updated Mar 13, 2020

Editor’s note: This is Rick’s abbreviated summary of Haneda et al.’s (2010, pp. 7-96) in-depth analysis and record of the disaster (published in Japanese, 2012 new edition here). Photos used to illustrate the summary are from the Daisetsuzan Range, but not associated with the disaster. A full report of the incident was also prepared by The Japan Mountain Guides Association (日本山岳ガイド協会), and is available on the web here (PDF in Japanese).

On 13 July 2009 the members of a tour group organized by the Tokyo adventure tourism company Amuse Travel (Amyuuzu Toraberu in Japanese) gathered in the lobby of Shin-Chitose Airport in Hokkaido. The 15 clients and three guides were to undertake a three day trek along the spine of the rugged Daisetsusan mountain range that rises to a number of peaks over 2000m in the centre of the island. Included in the itinerary were two mountains on the ‘100 Famous Peaks’ (hyakumeizan) list that has fuelled a massive boom in mountain walking among Japan’s senior citizens in the last twenty years.

The average age of the ten female and five male clients was 64, and most of them were well into their hyakumeizan campaigns. All had taken up or restarted mountain walking in their later years and most were repeat clients with Amuse or had been on similar organized mountain adventure tours. They were reasonably well equipped and carried three days supply of food. Of the three guides, who were meeting for the first time that day, the 61 year-old tour leader was a qualified mountain guide while the other two had experience of guiding for Amuse or other companies, but only one of them actually had firsthand knowledge of the intended route.

The weather forecast was for a low pressure system to pass over Hokkaido in the next couple of days, so the guides warned the clients to expect deteriorating conditions on their second and third days on the mountain. The first day’s (14 July) weather was fine and the group made good progress over the summit of Asahidake (2291m) to the first hut.

The second day it was raining, but visibility remained fair and the group reached the second hut in the early afternoon without incident. A number of the party, however, had managed to get wet from a combination of the rain, wet trails and overhanging vegetation despite having generally good equipment. The second hut was crowded and cramped, with no space to dry wet gear; some of the clients kept their wet clothes on in an attempt to dry them out. During the night the weather deteriorated further.

July 16 greeted the party with ferocious winds and squalls of rain. Nevertheless, the group set off from the hut at 5.30am into the teeth of the gale. The route from the hut to the summit of Mt. Tomuraushi (2141m) involves about 300m of ascent over 4km, mostly along a broadly defined ridge. In good conditions it should take about two and a half hours. After ascending a short snowfield where some of the clients had to be assisted in putting on their instep crampons, the group reached the main ridge and turned south towards the summit.

Here they encountered extremely strong winds from the west blowing at 20m/second accompanied by rain squalls. Progress along the broad and easy angled ridge became very slow and difficult, with clients repeatedly being blown off the path or off their feet, or having to crouch down in the face of the stronger gusts. In places there were fields of large boulders to be negotiated.

By the time the group reached Kitanuma, a small tarn on the shoulder of the mountain where the summit path branches off, some five hours had passed. A number of clients were beginning to display symptoms of hypothermia, one female client in particular unable to walk unaided and needing to be supported by a guide.

Further time was lost here fording the outflow of the tarn, which had turned into a 2m wide torrent. The guides helped most of the clients across one by one, while the others waited in an extremely exposed position in the full force of the wind. Yet more time was spent waiting while the guides attempted, unsuccessfully, to revive the female client. Finally, after one of the clients voiced concern, the guides conferred and the tour leader decided to bivouac on the spot with the unconscious client while the rest of the party would continue on the traverse path around the summit to the descent route. The guide and the client had an emergency shelter, but both perished from hypothermia within a few hours.

Once the remainder of the party began to move after the lengthy wait it quickly became apparent that three female clients were now also unable to walk. Within a few hundred meters the guides had again to make the decision to bivouac. One guide and a male client elected to remain with the three women in an emergency shelter. By about 4pm when conditions had slightly improved the guide left the bivouac to investigate a nearby camping area where by chance he found a tent, stove and some blankets that had been cached by workers repairing the trails. Returning with these to the bivouac he pitched the tent with the help of the male client and they attempted to revive the women. One responded to treatment but the other two died in the early evening.
In the meantime the third guide had attempted to lead the remaining ten clients off the mountain, although he was also by now suffering from hypothermia having fallen in the torrent at Kitanuma. Deciding that his priority was to raise the alarm he rushed off ahead down the path leaving the clients to follow as best they could. A male client collapsed and died soon after. Despite a lessening of the wind by this time and the desperate attempts by other members to assist, another three female clients lost consciousness and died near the top of the descent. Another woman bivouacked in her sleeping bag and survived the night. Having managed to raise the alarm by mobile phone the guide himself collapsed on the trail and was found unconscious the next morning by a rescue party.

Once alerted, the Mountain Rescue (a specialist police unit in Japan) and the Japan Self-Defense Force attempted helicopter flights but conditions were too bad. Only five members finally made it down to the lodge at the foot of the mountain at around midnight to find the Mountain Rescue teams fully mobilized. During the night the weather improved dramatically and in the early hours of the following morning the surviving clients and guides were rescued by helicopter.

Aftermath Notes (by Rick)

In the aftermath of the incident Amuse Travel was placed under police investigation and forced to suspend operations for nearly two months by the Japan Tourism Agency; it would eventually cease trading altogether after another incident in 2012 in which clients lost their lives. The disaster was the worst in a series of similar incidents involving senior citizens on guided mountain tours and prompted Japan’s adventure tourism industry to review guidelines, safety, guiding qualifications and risk management procedures. Although the immediate cause of death on Tomuraushi was hypothermia, it was clear that poor planning and decision making had played a central role. In particular, the pressure on the guides to keep to the schedule to avoid accommodation and flight cancellations was a major factor in their decision to press on in horrendous conditions. In March 2018, the police finally dropped charges of professional negligence against the company president and the surviving guides.

NOTE: Locations are approximate

Comments | Queries | Discussion

7 thoughts on “The Mt. Tomuraushi Incident”

  1. Boy, oh boy. There are some really interesting things about this incident.
    I would say, first, that a party of, what was it, eighteen people?, is going to be slow, slow, slow. It’s just huuge. Particularly if they are not screened with any particular rigor. Second, schedule inflexibility and multi-day walks over unknown terrain and variable conditions do not go together well, at all. One of the whole points of a longer walk, for many of us, at least, is to cut loose from this kind of thinking. Adapt to the conditions. Feeling tired? Take a rest day. Weather terrible? Stay in camp. If you can’t tolerate or afford that flexibility, do something else. Take a shorter, more predictable walk.
    I note that the trip was set up to stay in emergency shelters (非難小屋) both nights, and I’d be quite surprised if that was not against the rules. This does not give a favorable impression; and since these are first-come first-served shelters there is no guarantee that a very large party of 18 can fit in.
    But I guess that even in conscientious, rule-following Japan, there are bottom-feeders, corner-cutters, and people who take advantage.

    1. Yes, it’s verging on an abuse of the hut system for sure. Out of interest, I just did a quick internet search to see if these kinds of tours are still running. Sure enough, I found a similar itinerary using the two huts for the princely sum of ¥228,000 per person (admittedly including overnight ferry to and from Niigata to Otaru, though that isn’t actually very expensive), maximum 10 clients. Sounds like a profitable business. The blurb stresses it’s a hut based tour but participants may have to camp in some circumstances, presumably if the huts are busy. I’ve no idea if the tour operators make any contribution towards the upkeep of the huts.

  2. Pingback: Trekking the Daisetsuzan Grand Traverse in Hokkaido's Playground of the Gods | Tokyo Weekender

  3. Thanks for the article, it’s really interesting. Looking at the news reports of the time they state that 10 people died. Do you know if that number is factually inaccurate, or were two of those deaths linked to separate incidents in the area during the storm? Unfortunately, I can’t speak Japanese, so I’m unable to look at accompanied link. Thank you.

    1. Hi Thomas, thank you for the query. I can confirm that during that particular weather event, there were three separate incidents. 1) one elderly male solo hiker elsewhere in the Daisetsuzan Range died, 2) one female hiker near Biei-dake died, and 3) eight of the 18 person tour group died. All separate incidents associated with the bad weather event, for a total of 10 people killed (source:

  4. Yes, I believe that the conclusions are correct. The pressure is tremendous on tour-related activities to meet schedules at all costs….There is also a sense of gambare within groups engaged in physical activity in Japan that puts undue pressure on individuals to succeed, even at the expense of sensibilities. There is a time for pause, especially in the face of an angry Mother Nature. Go against her, and the cards are stacked against you.

    1. You are right, the guides can often be caught between annoying their employers and/or the clients when travel and accommodation arrangements get screwed up. As many are freelance they won’t get hired again if this happens too often. One thing that really shocked me when I looked into this was just how much the clients were being charged for this three day trip, especially as on two nights the accommodation was free. It was certainly a lucrative business.

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The Mt. Tomuraushi Incident Difficulty Rating





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GRADES range from A (very difficult) to D (easy). Hazards include exposure to avalanche and fall risk. More details here. Rating rubric adapted from Hokkaido Yukiyama Guidebook 北海道雪山ガイド.