2011-2012 Summaries

 

4/1/2012 Tuckerman Ravine–Crevasse fall fatality

At approximately 3:45pm, Norman Priebatsch was hiking with his son and two others when he fell on steep icy terrain. The group members reported that he fell over a rock band and began sliding downhill. The group received no response to their shouts as the victim slid downhill, and the victim was not attempting to stop his fall at the time. He slid into an open crevasse in the lower portion of the Bowl, below the Lip, in the vicinity of the “Open Book” area. The other members of the group immediately went to the edge of the crevasse, but could not make contact with the victim. One member, along with one bystander who was not part of the group, quickly went to the AMC caretakers’ cabin at Hermit Lake to report the accident.

2012-04-01 Crevasse

Circles in the Lip area mark the approximate location from which the victim fell and the location of the open crevasse at the top of the Open Book.

USFS Snow Rangers were notified of the accident shortly after 4pm. While the Snow Rangers made their way to Pinkham Notch, the AMC caretaker and other bystanders went to the ravine to gather more information and began preparing for the rescue effort. In addition to the USFS Snow Rangers, assistance was requested from Mountain Rescue Service of North Conway and Androscoggin Valley Search and Rescue of Gorham. The caretaker from the Harvard Mountaineering Club cabin also assisted at the scene, while the AMC staff at Pinkham Notch Visitor Center and the Mt. Washington Observatory provided organizational support and spot weather forecasts.

USFS Snow Rangers established two anchors for use in a technical rope rescue system. One Snow Ranger was lowered into the crevasse to a depth of about 40 feet. From this point, he could clearly see another 40 feet down. As the slope angle decreased, the crevasse narrowed to about 4 feet in diameter. There was no sign of the missing hiker in the area that could be seen. Due to the objective hazards involved in descending into the confined space, the decision was made to not descend farther into the crevasse. The Snow Ranger was raised back to the surface and rescue efforts were suspended for the night. Snow Rangers returned to the site the following day, but again the decision was made not to descend into the crevasse due to the hazards involved with such a recovery effort.

In the weeks following April 1st, Snow Rangers continued to monitor conditions in the area. Numerous attempts were made to visually check the crevasse, but further descents into the crevasse were not safely possible. On May 20th, Snow Rangers were able to safely descend underneath the snow using an access point located below and to the side of the waterfall. Using this new entry point, the victim was visible approximately 90 feet from the opening, or 125 feet below the original crevasse opening. That evening, plans were formed to recover the victim from the crevasse the following morning. On Monday morning, May 21st, the victim was recovered by a team of four Snow Rangers, with assistance from Androscoggin Valley Search and Rescue and the Appalachian Mountain Club caretaker.

Analysis

Earlier in the day on April 1st, two Snow Rangers had climbed through the Lip area, with the intention to assess and better understand the extent and severity of the crevasse hazard. They found crevasses to be very large and deep, though the magnitude of the hazard was not easily visible from above. They specifically looked into the opening that the victim later fell into. Climbing through the Lip, they also noted that the snow conditions that day were very hard and icy. These conditions and the Snow Rangers’ assessment were not unexpected. The avalanche advisory from that morning stated, “With the frozen surfaces comes the potential for very dangerous sliding falls. Every year we see numerous people climbing very steep and icy slopes (e.g. the Lip) without an ice axe and crampons…even very experienced mountaineers with all the right equipment would still have a very difficult time self-arresting under the current conditions on some slopes in Tuckerman, so play it safe.” It continued, “Climb up what you plan to descend. This gives you an opportunity to check for hazards such as crevasses at a leisurely pace.”

As mentioned in the advisory, having equipment is not a guarantee of safety. Down-climbing this route in these conditions is a very difficult endeavor; to do so safely would likely require facing into the slope and front-pointing one’s way down. The fact that three of the four group members were able to safely descend the Lip on this day is remarkable. None in the group were wearing winter mountaineering boots, no one besides the victim was wearing crampons, and though they did have ski poles, they were not carrying ice axes. In this very unfortunate accident, it would be an over-simplification to blame the lack of an ice axe as the primary cause of the accident, but this could be considered one contributing factor.

The Mount Washington Avalanche Center often recommends springtime visitors hike up what they plan to descend. We make this recommendation to backcountry visitors regardless of their level of experience. Every season brings similar hazards of crevasses, undermined snow, icefall, etc., but throughout each season the location, severity, and extent of the hazards does change. In this particular situation, the party had ascended a different route than they descended, so they did not have the opportunity to assess the extent of the crevasses before descending. When Snow Rangers were checking the conditions earlier on the day of the accident, it was using roped climbing techniques and utilizing an avalanche probe to locate, evaluate, and avoid crevasses. Despite this technique, one Snow Ranger inadvertently broke through a snow bridge and nearly fell downslope. If this had happened, the rope safety system as mitigation would have prevented a long sliding fall. This roped and probing technique is rarely used by spring visitors to Mt. Washington, even though it would be considered standard practice for mountaineers in other glaciated mountain ranges.

Each visitor, according to his or her experience and skill set, should be prepared for the current conditions. It is important to understand that what may be a reasonable level of risk for one person may not be the same for another, and that each person or group is responsible for deciding when, where, and how to travel. It is also important to understand that no person begins his or her life with mountaineering experience. There is no better way to learn safe mountain travel than through the actual experience of traveling in the mountains. It is imperative to honestly evaluate one’s own experience, skill, and tolerance for risk.

 3/18/2012 Lion Head Trail

A hiker injured her knee while descending from the summit.  USFS Snow Rangers encountered the woman, who was a member of a guided party, at the Tuckerman/Lion Head Summer Route trail junction and transported the patient to Pinkham Notch via snowmobile drawn litter.

3/18/2012 Tuckerman Ravine

A skier was injured while booting up the Chute when he attempted to stop another falling skier.  The patient suffered a 2″ laceration to the left ear.  MWVSP members treated and released the patient.  The falling skier was uninjured.

3/17/2012 Tuckerman Ravine

A skier fell near the top of the Chute, slid to about the Narrows and then “log-rolled” before finally stopping about 200′ above and right Gumdrop Rocks. Witnesses reported that the skier, who was skiing for his first time in Tuckerman Ravine, took about 2 turns and pre-released from the binding of one ski.  Mount Washington Volunteer Ski Patrol members and USFS Snow Rangers responded, treated and packaged the patient who was unconscious and seizing on arrival.  It is unclear whether or not he impacted any rocks during the fall.

Due to the presentation of symptoms and the calm winds, a helicopter evacuation was ordered.  Lifeflight of Maine, flying out of Bangor, transported the patient to Maine Med in Portland. The ability to fly into Tuckerman Ravine is very unusual due to the preponderance of days with turbulence,  high winds, limited visibility, limited landing options or all four factors at once.  Fortunately, a relatively limited number of skiers were in the bowl, which reduced the risk and consequence of mishap with the helicopter.

1/9/2012 Tuckerman Ravine

A solo hiker died as a result of injuries sustained in a fall while descending in the vicinity the Lip area of Tuckerman Ravine. The fall was witnessed by the AMC caretaker at Hermit Lake Shelters, who immediately notified USFS Snow Rangers and initiated rescue efforts. Despite the fact that rescue was immediately begun, the victim passed away while rescuers were preparing for the evacuation.

1/8/2012 Tuckerman Ravine

USFS Snow Rangers were heading home at the end of the day Sunday when notified of hikers having dialed 911 from Mt. Washington. Apparently, two hikers were attempting to descend the Tuckerman Ravine Trail through the ravine, when one of them slipped and fell. He was able to self-arrest, but somehow lost track of his partner. Thinking his partner had also fallen, he called 911 for assistance. After making the call, he was able to locate his partner above. He and his partner eventually found their way to and descended the Lion Head Trail. The HMC caretaker made contact with the party on the lower portion of the Tuckerman Ravine Trail, confirmed that they had made the distress call, and did not need further assistance.

1/5/2012 Huntington Ravine – Central Gully

A party of two was climbing Central Gully when the leader was hit with a naturally-triggered sluff avalanche. During the fall, one of the climbers fractured his ankle. Much of the information below was gathered from a narrative provided by a guide who was in the area as well as from conversations with the injured party.

Just prior to the incident, the guided group climbed up to top of the ice bulge in Central. The guide decided not to continue up the gully due to excessive spindrift, blowing snow, and generally harsh conditions above treeline. He had a 3-ice screw anchor built for his group in the ice. When the party of two arrived, he allowed them to clip the anchor while they climbed the ice. However, after the group cleared the ice they were climbing unprotected with a short rope between them.

At this point the guide was at the top belay, out of the fall line, while his clients were down at an ice screw anchor below the ice and also out of the fall line. About 15 meters above the ice, the party of two was hit with a loose snow (sluff) avalanche which carried them both downslope. According to the leader, the force felt as though he received a stiff push or kick in the chest. The guide heard “Avalanche!” but did not see the falling climbers pass by. He descended down to his clients to get them situated. He assumed that the slide had happened below him and that the party of two was still up in the gully. About 10 minutes later he heard a call for help. The party had fallen about 100m, coming to rest about 30m below the fracture line from two days earlier. It was the second climber who sustained the ankle injury. The lead climber was uninjured but did break his climbing helmet in the fall. It wasn’t until he descended to the injured party that he learned it was the climbers above who had been avalanched past.

With help from his clients and the partner of injured climber, the guide was able to lower the patient down toward the bottom of the fan. At this point two clients went to the rescue cache to bring up a litter. The guide had been able to wrap the patient in a bivy bag and help keep him warm with a water bottle of hot tea placed between his legs. The patient was then placed in the litter and they worked their way down to the Harvard Cabin. From the time of the accident (2pm) to the time they arrived at the cabin (6pm) was about 4 hours. Their efforts are very much appreciated, since the trail from the bottom of the fan to the Cabin is very difficult for a litter carry in these lean snow conditions.

USFS Snow Rangers met the group at the Harvard Cabin, reassessed and re-splinted the injured leg. From arrival at the cabin to the parking lot at Pinkham was about 2 more hours. The litter was sledded down the Sherburne Ski Trail by USFS Snow Rangers, MRS and students from SOLO who were at Pinkham for a Wilderness First Responder course.

We received word afterwards that the patient did indeed break his ankle, which will require surgical repair. This day (January 5) was the first 5-scale avalanche advisory for Huntington Ravine this season. The advisory for the day indicated Huntington Ravine starting the day at Low danger, but moving into the Moderate rating as a forecasted 1-3” loaded in on W and NW winds. The summit did record 2.4” of new snow on January 5 with winds averaging 56mph.

1/3/2012 Huntington Ravine – Central Gully

Two skiers triggered a R2D1.5 avalanche in Central gully at approximately 2:30 in the afternoon. The previous night 2.9 inches of new snow fell on the summit with strong winds. During the morning and through the day this snow was transported into the deposition area below the Central ice bulge. Both Tuckerman and Huntington Ravines were under a General Advisory identifying snow stability concerns in isolated snowfields in each of the ravines.

Taken by skier #2 during approach

In the words of skier #2: ” The sky was mostly clear with a lot of blowing snow, which should have been our first sign of newly loaded snow in the gullies. We moved our way up the hiking trail through the fan of the ravine carrying our skis on our packs. Halfway up the fan we broke left onto the snow fields in front of Pinnacle buttress and gully. Here we turned on our beacons and did a beacon check to make sure our transceivers were working in transmit and search mode: they were and we read in each others distance from one another approximately the same. With the high winds, cold and strong gusts, we decided to dig multiple quick/hasty pits as we ascended the snow. We found a lot of spatial variability up the slope. Scoured old icy surface, very dense heavy 2″ slab, 8-12″ lighter slabs, some of these slabs were right on old surface and some were sitting on top of what seemed to be consolidated snow. The cold temps and the winds were not friendly to digging more comprehensive pits, something we should have used as a sign that it was “not a nice day to go skiing” but we pushed on to the Central buttress where we found a large patch of recently (and still being) deposited snow. At the base of the ice route known as Cloud Walkers we began inspecting this new and different snow and kept digging around and feeling for layers in the snow as we climbed. There seemed to be no inconsistencies in this wind slab.  Punching ski poles and our arms up to our shoulder we found the same type of snow as deep as we could determine with the assessment/observation technique we were utilizing. Climbing through this area of snow, postholing up to our waists at times, we made our way to the base of the ice slab in Central gully and tucked ourselves away into the corner of the rock climb known as Mechanics Route, which ended being a very good idea in retrospect. ”

The first skier started out and after one or two turns triggered a slab avalanche that carried the skier approximately 500 feet down into the fan, over snow, and fortunately not into the talus. The seconds skier standing along the buttress (skiers right) was not caught in the release and was able to move down the slope to help.

Skier#2: “I hurried down to a flatter spot where I left my skies and poles, pulled out my beacon and turned it on to search mode pointing it in the direction my partner had been swept toward. Taking a moment to make sure the beacon was indeed in search mode I found no signal, he was still too far away down hill. I began moving down through the rock fields, more or less on the hiking trail, adjacent to where the slide had flowed past. Visibility was difficult at a distance but I could see the debris from the slide. Most of it had been broken into small chunks of snow and some were still basketball size. I quickly moved downhill in a straight line  scanning left and right to try to pick up his signal. Looking back and forth from my beacon to the direction I was heading, I soon saw a figure about five hundred feet below me moving from where I saw the slide go toward to where I was heading in the rock fields. It seemed to be my partner carrying his skis to a safer place away from the slide area.”

Doing a quick check on crown height.

Snow Ranger doing a quick check on crown height.

Discussion:

In our experience looking at avalanche accidents and close calls on Mount Washington over the years, constant themes, mistakes, and oversights arise.  Many of them are related to human psychological factors, the mental drivers that whisper over our shoulder “..everything is fine, good ahead you’ll have fun, you’ve done this before…”,  while others miss the bulls-eye data that Mother Nature is offering and not having as much avalanche knowledge as we all should.  These are traps any of us can fall into, which highlights how important it is to approach avalanche terrain with skepticism and keep asking the critical questions.

In this particular case a number of things were done well and some factors were overlooked.  Good partner accountability and the ability to be support for our fellow partner is always important.  Sound rescue skills and a level head to execute under duress is what all of us want in our mountain team.  Beacon checks, going one at a time, good rescue execution are excellent practices and are commended in this case.  Having a good plan in case of an incident is critical, but focusing on and planning for rescue should not take a front seat to all the actions we should consider in order to not get caught.  It’s all about not getting caught, not avalanche rescue. New Hampshire leads the nation in the percentage of avalanche deaths resulting in trauma.  Based on our terrain and low snowfall an avalanche can often send you through the trees and rocks.  This results in a higher probability that you’ll be deceased when the snow stops more than any other state.  The avalanche beacon is of little value in this scenario.  So, avalanche rescue skills and gear are always extremely critical, but never more important than knowing how not to get caught.

In hindsight our vision is 20/20 as we ask ourselves “how could we have overlooked these clues?”  This is especially true with the objective facts we would expect to ask ourselves.  How much precipitation did we receive in the past 24/48 hours?  What direction are the winds and at what speed?  Is my intended terrain in the lee?  Do I have the slope angle and adequate bed surfaces for avalanche potential?  All these taken together will often send up some red flags.  After these questions are answered you’ve got some data, now what?  “What’s the stability like.”  Snow pits and stability tests can be a double edged sword.  They are critical to have an understanding what is going on under the surface.  Stability tests such as Compression Tests, Extended Column Tests, the Rutschbloc, etc. give you some indication how slopes might react as opposed to quick hasty digging (sans tests) which can bring out red flag layers or crystals, but are limited in what they tell us about how the slope might respond to your load.  The other edge of the sword in doing stability tests is they tell you what is going on right there and not accounting for potentially vast amounts of spatial variability.  As this team went upslope they recognized variability which led to a choice to not spend too much effort or time in one pit which is not an unreasonable decision.  There is a possibility that numerous pits would lead them to believe skiing the slope was a reasonable proposition.  In our terrain spatial variability often increases the odds of  “false stable” results when doing stability tests on a particular slope. Basically, stability tests can lead you to believe a slope is stable when in fact it’s not. No matter what mountain you’re on around the world knowing what’s buried 10-20 meters out in the middle of a couloirs is often the 64 thousand dollar question.

In this case, as best we can surmise, the initial fracture leading to failure occurred in a very thin section of the slab over water ice unseen from the surface.  It is very probable faceted snow sat between the ice and the thin slab (+/- 15-22cm) causing a failure back into the deeper slabs behind the first skier.  Given the same weak layer your “impact bulb” causes more stress on a shallow weakness than a deeper one.  The thicker a slab (i.e. +/- 80 to 100cm) the more it generally distributes your load over a broad area on a weak layer. In a thin slab (i.e. +/- 10-40cm) a point load of the same weight impacts the weakness with a greater amount of pounds per square inch generating a more likelihood of fracture and failure.

20 hours after the incident two crown line profiles were done in a +/- 12 meter section of the 30 m overall crown length.  This section was fairly consistent at 90cm deep before tapering rapidly after a rock in the crown.  A score of CT11 with Q2 shear occurred in both profiles failing at 90cm.  Although a number of layers existed above the test failures at 90cm they survived the CT11 tests.
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