ABSTRACT
Although the Progressive Collapse of structures is a rare event, several such incidents form well known landmarks in the history of Structural Engineering e.g. Ronan Point, Murragh Building, World Trade Centre etc. As a result the obligations on designers to demonstrate that they have properly considered the possibility and have made adequate provision in their designs have increased substantially in the half century since the collapse due to a modest gas explosion of one corner of a system built precast concrete apartment building in East London (Griffiths et al. 1986) shown in Figure 1.
