This answer discusses the failure of the Ronan Point tower block, highlighting the issues in construction and building regulations.
What caused the failure of the Ronan Point tower block?
In 1968 the entire south-east corner of Ronan Point in Newham, East London, collapsed, after a resident, Ivy Hodge, struck a match in her kitchen on the 18th floor, causing a gas explosion. The building, a 22-storey tower block, had been constructed using a Large Panel System. In this system pre-fabricated concrete sections were completed off-site and then built up on-site with use of a crane and bolted together. The explosion caused the load-bearing walls of Hodge’s flat to be blown out, leaving the floors above unsupported, leading to their collapse. Due to weaknesses in the connections between vertical walls and floor slabs in the floors below, this sudden load lead to the progressive collapse of all the flats below Hodge, on this side of the building. Four of the residents were killed instantly, and a further seventeen were injured in the collapse.
An enquiry found that, while the building complied with regulations at the time, the walls could not withstand pressures from small explosions, and could not have held up against unusually high wind speeds or bowing caused by fire. As such building regulations were updated and the building was partially rebuilt using strengthened joints.
Some architects involved in the enquiry, however, were not satisfied that the building was safe, due to a number of other issues with the quality of construction itself. There were a number of unfilled gaps between floors and walls, leaving the building without fire separation, to prevent fires from lower floors spreading upwards. Also the connections between floors were found to be insufficient, with all the force transferred through steel rods, rather than spread evenly across the surfaces, resulting in areas of high stress.
The building was eventually evacuated and demolished in 1986, in a forensic manner, so that the extent of the construction issues could be fully assessed. A number of cracks were found in the concrete in lower levels and it was alleged that particularly high winds would have led to the building’s total collapse.