2020 Gjerdrum landslide

The 2020 Gjerdrum landslide was a quick clay landslide that occurred in the early hours of 30 December 2020 at Ask village, the administrative centre of Gjerdrum, Norway. It spanned a flow off area of and additionally affected by debris flow. Several buildings were destroyed, most of them houses and apartment buildings. 
As of February 9th, 2021, nine people had been confirmed killed by the landslide, while one remains missing.
The causes of the landslide will be investigated by police; another investigation, tasked with finding - prior to August 2021 - the causes of the landslide, will be performed by a group of experts.
Background.
There have previously been landslides in Gjerdrum municipality. During the night between 20 and 21 October 1924, a landslide destroyed several farms and damaged 1600 metres of road. In 1973 there was a landslide at Ask. A 1980 landslide was near the south end of the 2020 landslide. In 2014, a landslide destroyed two houses.
In July 2008, an article published in "Romerikes Blad" stated that hydrologist and geologist Steinar Myrabø had warned the municipality of soil erosion and the potential risk of a landslide, calling for a halt in construction at Nystulia on behalf of Norwegian Society for the Conservation of Nature's local chapter. In November 2020 a hiking path was constructed 150 m westwards of the later slide area. The photos of heavy machinery initiated public concern. But the path and the slide area are separated by two small ridges and the Fjelstadbekken stream. 
According to the broadcaster NRK, intense rain in the days before the incident may have caused soil movements in the area. The Nannestad municipality next to Gjerdrum evacuated a hamlet on 15. December 2020 after a small landslide nearby.
Search and recovery operations.
The first reports of the landslide were made at 3:51am on 30 December 2020. 10 people were injured, with 26 initially reported missing, though it was later determined that the actual number of missing persons was 10.
On New Year's Day, assistance from Sweden was requested; a 14-person Urban Search and Rescue team from Sweden worked onsite, and was released the same evening after the arrival of additional Norwegian rescue personnel.
By January 1st 2021, details of the ten people missing were published by police. The same day, the first casualty was reported. Early on 2 January, the body of a second victim was found, and later that day two more people were found dead. On 3 January, three more people were found dead, bringing the death toll to seven. Three people still remained missing, with searches continuing.
On January 5th, 2021, the Norwegian authorities stated they no longer held out any hope of finding further survivors. At that time, three people were still missing.
A video released by the police on January 6th shows a rescue helicopter over the avalanche, searching for survivors. The video is filmed from a police helicopter, and from the communications one can hear how they are trying to guide the rescue helicopter to the potential survivors' location.
Victims.
The names of the victims were made public on 1 January, with the permission of their families.
Search for presumed dead.
On 5 January the police stated that they no longer held out any hope of finding more survivors, but would continue the search for the last three victims.
The same day the Norwegian Armed Forces and their equipment left the area, with only the Home Guard left on the scene till 12 January
The Norwegian Civil Defence terminated their mission on 15 January and a civilian security company continued to guard the affected areas.
After a two weeks break the search for the remaining missing victims continued from January 18.
On February 9th, 2021 two bodies were located by search teams searching for the three remaining missing victims.
On March 22 the last missing person was found.
Mobilized resources.
Many government and private organizations, military units and volunteer organizations were involved in the search and recovery operation:
Aftermath.
The Nannestad and Gjerdrum Red Cross received large amounts of donations of toys, clothing, and hygiene products for the survivors of the landslide.
Following the disaster, several news outlets revealed that the affected area had been designated as a high-risk area for landslides as early as 2005 and that it was scheduled for a new evaluation in 2021 due to the increased amount of housing and construction projects in the area.
Several experts and engineers later criticized the Norwegian national government as well as local government for not taking high-risk areas seriously and allowing housing projects to continue despite having "clear instructions of how to deal with these areas for over fifty years."
Reactions.
Prime Minister Erna Solberg visited the affected area on 31 December 2020, and King Harald V dedicated parts of his New Year's Speech to those affected by the disaster. 
The King of Sweden, Carl XVI Gustaf, also publicly expressed his sympathies the following day. The President of Finland Sauli Niinistö and the Prime Minister Sanna Marin also expressed their condolences to the Norwegian government and people.
On 3 January 2021, King Harald V, Queen Sonja and Crown Prince Haakon visited the disaster area to speak with rescuers, volunteers, evacuees and their relatives.