The collapse of WT 7

An overview of the factors that led to the collapse of World Trade Center (WTC) 7, a 47-storey building located across the street north of the twin towers, is presented. The factors outlined are based on the preliminary assessment contained in the US Federal Emergency Management Agency (FEMA) report of the year 2002. Fire development and fire resistance issues played a major role in the collapse of WTC 7. The debris from the collapse of the twin towers is though to have initiated fires at multiple floors of the building. The loss of fire defences, including sprinklers and active firefighting, further contributed to weakening of the structural members.