When that layer of ice began to melt, small particles of clay flowed with it and was deposited in salt water along the coast.
[1] With the weight of the ice dissipating as it melted, the land below it began to slowly rise up to where the coast is now between 220 and 300 metres above the marine level.
[1] When undisturbed, quick clay behaves like a solid, however when placed under sufficient stress it acts more like a fluid through a process known as soil liquefaction.
[2] Quick clay has been the cause of a number of landslides and sinkholes, with 250 such sites being identified in a 60 kilometre radius of Ottawa.
[9] The Västra Götaland County administrative board had previously stated to the local municipality that the land was unsuitable for development in 2020 and that there was a risk for a landslide to occur, with the Swedish Geotechnical Institute [sv] concurring.
[10] Approximately 10 vehicles were affected by the landslide, including seven cars, lorries that were parked in a rest area and a bus which had no passengers at the time.
A spokesperson for the Swedish police stated that the incident was expected to cause "enormous" consequences for traffic in the area for the foreseeable future.
The Swedish government also provided the STA with an additional SEK1 billion (US$116.55 million) so that the road could be reconstructed without impairing planned maintenance in other areas.
[21][24] On 14 November 2023, there was an accident in which a head on collision occurred between a bus and a car on O650, with a woman being transported to hospital by helicopter with serious injuries.
[25][26] The original plan was for the damaged sections of the E6 to be repaired by the end of 2024, however this was completed ahead of schedule, leading to a revised aim for the road to be reopened by mid-2024.
[27] In an effort to improve stability, a layer of crushed, recycled glass several metres deep was placed below the road.
[18][29] Traffic was officially released at 03:00 that day,[30] and over 100 Ucklum residents hosted a celebration "with sausages and bouncy castles".
[32][33] The cause of the landslide was initially unclear, with Swedish media identifying that blasting and excavation had been taking place at the business park development and the heavy rainfall that had been ongoing over the days prior.