Within a couple of decades of the collapse of Ronan Point, the public's lack of confidence in the LPS construction technique, together with the social problems within such developments, led to the demolition of many tower blocks. Despite this, many buildings like Ronan Point are still standing; there are at least 1,585 of them and 200 towers with 20 storeys or higher. There are concerns that problems might emerge as the buildings weaken with age. Wind, heat and rain affect buildings. Metal bolts expand when they rust and crack the concrete round them. In 2018, it was reported that two tower blocks on the Broadwater Farm estate in Tottenham, Tangmere House and Northholt House, are structurally unsound and could collapse catastrophically if there is a gas explosion or if a vehicle collides with the base. Both are to be evacuated urgently. Other buildings in Broadwater Farm also have less serious problems.