A substantial rockfall occurred Sunday afternoon in central Oslo near Carl Berners Square. Large rock masses detached from a cliff between two residential buildings in the Hasleveien area.
Geology professor Ola Fredin from the Norwegian University of Science and Technology analyzed the site. He noted the cliff appeared secured with rock barriers and netting, but these measures failed to contain the massive rock block that collapsed.
"Obviously it wasn't secured well enough," Professor Fredin stated. "The netting and barriers weren't designed to handle a block of this size."
He explained that rock netting typically stops smaller stones, about the size of a basketball at most. This incident involved dozens of tons of material, possibly much more. A single cubic meter of rock weighs approximately 2.5 tons.
The cause remains under investigation, though Fredin suggested prolonged rainfall could be a factor. Water entering geological cracks can act as lubrication in unstable zones. Meteorological data shows above-average rainfall in the area during September and October.
Between 300 and 400 residents were evacuated and gathered safely at a parking lot away from the danger zone.
The property owner, the Oslo Student Union, received warnings about potentially dangerous conditions back in 2021. Municipal authorities had documented that the slope consisted of shale rock with loose stones behind existing netting.
The organization's managing director acknowledged the previous warning. "We're obviously familiar with that notice and we followed up on it," he said in a statement. He confirmed they conducted security work and removed loose material, with annual inspections since then.
The director could not specify when the most recent inspection occurred. He called the incident "serious" but deferred detailed comments pending geological investigations.
Geologists examined the site Sunday evening, with investigations continuing Monday morning.
The gap between the 2021 warning and this major collapse raises legitimate questions about maintenance protocols for at-risk urban areas. When safety warnings identify specific hazards, timely and adequate response becomes crucial for public protection.