The expert group presented its report at a press conference on Monday 12 December at 12.00. – The reason lies in the development of the new E39, said Lars Andresen. He is the leader of the expert group and managing director of the Norwegian Geotechnical Institute (NGI). The landslide occurred on Friday evening 2 September in the village of Hennset by Valsøyfjord in Heim municipality in Trøndelag. Present when the expert group presented its first causal report were the siblings Stein Terje Hendset and Bodil Brandsæter. An entire house was destroyed by the avalanche. Photo: Bjarte Johannesen / news The siblings’ childhood home was taken by the avalanche, and their mother Bjørg Hendset died in the accident. Six people were sent to hospital, including a two-year-old who was rescued from the house. Tried to get away Hendset and Brandsæter were both inside the house when the avalanche started. They had gathered there with their family to have a pleasant Friday evening. But only dramatic memories remain. – We drove from Trondheim on Friday and were supposed to have a nice weekend. We gathered in my mother’s living room, says Hendset. When they suddenly saw a shadow disappear, they first thought it was an overturned truck. – But just a few seconds later, my sister says: “Jump!” Then we saw that the forest was coming towards us at extreme speed. We tried to get away as best we could, but we didn’t get very far. It was the siblings’ mother who died in the avalanche accident. Photo: Morten Andersen / news They both saw the forest coming straight towards the living room and the window they were sitting next to. – I actually came the farthest. I was 30 cm from a wall, so that I saved so that I was not injured more. I had refrigerators and kitchen cabinets and various equipment thrown over me, but I managed to get free, says Brandsæter. The hand was hit in the head by the door frame, and was thrown around. – I woke up in the basement – or at least below where I was standing. I had the stove above my feet, and the fireplace and chimney were directly above and beside me. I couldn’t get free. He had the phone in his hand, and notified himself of the accident. – I thought myself that I was the only one who had survived. I realized that this could not go well, says Hendset. – That’s what we all thought. That there is only me left, says the sister. Still affected You are sure that the whole family will be affected by this for a long time to come. – We are doing well, but there will be long-term damage and a lot still needs to be done. My daughter has had an operation on her back and will have to have several operations on her back to finish. My son has also had an operation and will have more operations. I have problems with my neck and tinnitus, says Hendset. – We are still physically and psychologically affected by it, and we will be for a long time. At the top of the picture you can see the construction area for the new E39. The landslide went from here and over the current E39, which is just above the water’s edge. Photo: Marius André Jenssen Stenberg / news In the area, work is taking place on the construction of the new E39, and work was being done on a construction road a few meters opposite the damaged house when the landslide occurred. Already the day after the landslide, the Norwegian Public Roads Administration confirmed that the construction work could have been the trigger. This is also the expert group’s conclusion after three months of investigation. Two triggering factors In the work, the group has looked at how the road construction work has proceeded, in addition to assessing the terrain, geological, hydrological and hydrometeorological conditions. They have also conducted interviews of witnesses and those affected. The expert group points to two triggering factors: Increased supply of water to the loose masses in the landslide area. Overloading of the slope as a result of filling in soil masses. During the press conference, Lars Andresen referred to the filling of land masses as the likely direct triggering cause. The expert group made a statement about the cause of the landslide at Valsøyfjord at a press conference on Monday. Video: NGI Andresen explained that the development work has inadvertently diverted water from the local Torbugbekken’s catchment area to the landslide area. In addition, July was twice as wet as normal. – We see that several measures have probably short-circuited some of the natural waterways and brought water into the area, he said. The CEO of NGI, Lars Andresen, is also the leader of the expert group that has investigated the landslide. He presented the findings in a press conference in Trondheim on Monday. Photo: Morten Andersen / news He went on to say that on the evening of 2 September, masses of soil were moved from the upper side to the lower side of a construction road. This led to an overload of the slope with the soft loose masses. – The soaking of the masses made the ground more unstable, and when you get an additional load on the masses by putting soil masses on top, it triggers the landslide. According to Andresen, it was an area of approximately 30 by 30 meters that came loose. – According to our assessment, there were approximately 1,500 cubic meters of soil masses, which are wet and become very liquid and thus flow downwards. The expert group visited the area shortly after the landslide. The group consists of Lars Andresen (NGI), Anders Beitnes (WSP Norway), Johan Arnt Vatnan (Cajun Management AS), Arnstein Watn (NTNU) and Ingrid Havnen (NVE). Photo: Jøte Toftaker / news Agree – Now we have received an oral, brief briefing and received the report in our hands, so we will read the wording thoroughly before we see what needs to be done next. That’s what the family’s spokesperson Per Sefland says. According to him, the report agrees with what the family has experienced during the summer and the road construction project. They had noticed that a stream had dried up, and that there were changes in the water conditions. – It is not that often they have been there, but when they have been there it has been a cross of thought for them, says Sefland. Per Sefland, the family’s spokesperson, believes it is very important to get clarity on the causal relationships. Photo: Morten Andersen / news – Tragic incident The expert group was appointed by the National Road Administration shortly after the landslide and their report is handed over to the Road Administration by project director Ove Nesje. – This is a reminder of a tragic incident that we should have avoided, says Nesje to news. – The report also documents what we actually thought was the cause, and is a good confirmation of that. This is what the landslide area looks like today. Photo: John J. Storholt Nesje believes that the expert group has done a good and thorough job, which is important to understand what happened, so that it can be prevented from happening again. However, he does not want to go into detail about what could possibly have been done differently in connection with the road work, and refers to the expert group continuing with more detailed work to find learning and improvement points. This report is expected before Easter 2023. – That work will also intervene in responsibilities, and it is the expert group that must find out the causes and whether there is something that should have been done differently. Any criminal consequences are for the police to assess. The incident is still under investigation. Project director in the National Roads Administration, Ove Nesje, calls the landslide accident terribly tragic. Photo: Morten Andersen / news The road work was put on hold as a result of the landslide, but resumed as early as the following Monday. Then with increased geotechnical expertise and with new risk assessments as a basis. Nesje says that the work has gone well, but that it has also been difficult. – Both we and the contractor’s people are affected by this, in the same way as those who live in the area. Do not drill in the area In planning work and risk analyzes in advance of the road work, no pronounced danger of landslides has emerged in the area, and NVE has not demarcated danger zones there either. In geotechnical reports from 2014 and 2020, however, further drilling and test excavations in the area were recommended, in order to get a better assessment of the stability of the ground. Shortly after the landslide, the Norwegian Public Roads Administration was able to confirm that such additional ground surveys had been planned, but that there was no drilling in the area of the landslide at the time. Changes in water conditions in the area were also pointed out after the landslide. A geologist also told news that frequent periods of rainfall lead to an increased risk of landslides, and that this is something that must be taken into account in excavations. The geologist believed that the people should never have been in the house. The pair of siblings who grew up here think it is strange to go back now. – It’s very strange – I’ve been there quite a bit before it was demolished and now after it was demolished. You have an image in your head for over 50 years, and then it is completely different. It’s completely incomprehensible, really. Because you don’t think something like that will happen, says Svein Terje Hendset. A few tens of meters above the house that was taken by the landslide, a construction road had been built in connection with the road construction. It is this road that you see in the foreground – in the middle of the picture you see the remains of the house. Photo: Morten Andersen / news
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The expert group presents a causal report after the landslide at Valsøyfjorden in Heim municipality – news Trøndelag
