The incident occurred on Monday, November 2, 2020, in Chelsea, west London. The two structures were under renovation works when both were suddenly reduced to rubble.
The collapse was followed by an intense sound and debris was dispersed in the nearby streets. “I live in the area and was just passing by when the building suddenly collapsed to the ground. It was extremely loud, there was dust everywhere. There were a lot of people coming out of their homes in the surrounding area to see what was going on, they were unharmed," a local, stated.
Firefighters rushed to the site in search of potential victims. There are still no reports about injuries associated with the failures. Fortunately, no one used to live in the affected structures. However, 40 nearby residents were forced to evacuate their houses for safety reasons.
The causes of the collapse have not been identified yet. According to neighbors, renovations works were being conducted in the basements of the buildings, a fact that probably deteriorated their structural integrity. An unofficial source claims that a scaffold came crashing down before the entire structures give way.
Permission for the development works in the first house was granted by Kensington and Chelsea council in the summer, 2020, and the renovation works mostly impacted the ground floor of the building. Nevertheless, warnings about potential failures were issued by the council if reconstruction works were not being conducted according to the regulations. Regarding the second house, an application for renovation works was submitted around 15 days ago. According to the Kensington and Chelsea council, those works included: "basement excavation, demolition of extension and roof terrace and replacement with a two-story rear extension with roof terrace, and a single-story extension at the lower ground floor".
A team of structural engineers was dispatched to the scene to evaluate the causes of the collapse and to find a way to secure the area. Those who were forced to evacuate their homes, were allowed to return after evaluations were completed.
At least 3 more houses in the same streets are currently undergoing renovations works and authorities should be alert to prevent similar failures.
Basement and garden renovations are common in London's wealthy districts. New endeavors include multiple underground floors that may lie 18 meters below the ground. There are also subsequent underground structures in London that accommodate various facilities including bars, music halls, gyms, libraries etc.
The real estate prices in the area are very high. In the same neighborhood, a seven-bedroom residence was sold for about $20.9 million in 2019.