Coastal bluff collapse damages backyards in Rancho Palos Verdes, California
A section of coastal bluff measuring about 91–122 m (300–400 feet) collapsed in Rancho Palos Verdes, California, on September 28, 2025, falling 15–18 m (50–60 feet) toward the ocean. Four backyards were damaged, but no homes sustained structural damage, and no injuries were reported. Authorities said the collapse occurred outside the long-active Portuguese Bend Landslide Complex, located about 6 km (4 miles) away.
A large section of coastal bluff collapsed on the evening of September 28 in Rancho Palos Verdes, Los Angeles County, damaging private property but leaving homes structurally intact. A city geologist examined the site and concluded the movement is currently static.
City officials confirmed that approximately 91–122 m (300–400 feet) of bluff gave way, dropping 15–18 m (50–60 feet) toward the shoreline. Four backyards were affected, but no injuries or structural damage were reported.
The incident occurred near Marguerite Drive, where multi-million-dollar homes overlook the Pacific. The area has been cordoned off by the Los Angeles County Fire Department, and the public has been advised to avoid the shoreline.
Officials said the collapse is not part of the Portuguese Bend Landslide Complex, an active slide zone about 6 km (4 miles) southeast that has been moving intermittently since 1956 and destroyed around 140 homes in the decades since.
Rancho Palos Verdes is situated on the Palos Verdes Peninsula, a region known for multiple active and dormant landslides, including Portuguese Bend, Abalone Cove, Klondike Canyon, and the Beach Club slides. The Portuguese Bend landslide was reactivated in 1956 following road construction, and extensive ground deformation has continued there for decades.
Recent NASA airborne radar surveys in fall 2024 detected displacements of up to 10 cm (4 inches) per week in parts of the Portuguese Bend landslide zone, with imagery showing expansion of the active slide area beyond historical boundaries. The measurements align with boundaries mapped by the California Geological Survey in 2007.
Geological studies attribute instability in the region to mechanically weak sedimentary formations, groundwater pressures that reduce slope stability, and continuous coastal erosion that undercuts bluff faces.
While such processes are understood to influence long-term instability, the exact cause of the latest collapse remains under investigation.
City officials have renewed calls for changes in California law that would classify landslides and climate-related ground failures as state emergencies, unlocking faster access to funding and response resources.
Rancho Palos Verdes maintains landslide parcel mapping and regularly issues land-movement updates through official monitoring programs. In 1978, the city adopted restrictions prohibiting new residential development within the Portuguese Bend Landslide Complex to reduce future exposure to ground failure.
Featured image credit: KTLA (stillshot from the video)
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