A survey of the fire-damaged structure of the Windsor Tower, Madrid, concluded that the concrete structure 'performed extraordinarily well in a severe fire'. The study, 'Fire in the Windsor Building, Madrid: Survey of the Fire Resistance and Residual Bearing Capacity of the Structure after the Fire', was carried out by the Instituto Technico de Materiales y Construcciones. It concluded that the 'need for - reproofing of steel members to guarantee their performance in the event of - re was recon-rmed'. The fire started on the 21st oor of the 32-storey building in February 2005. It spread quickly due to a lack of fire stops between the curtain wall facade and the concrete oor slabs. Designed and built in the 1970s, traditional design methods were used. Extensive refurbishment was under way at the time of the fire, including measures to bring the building's fire standards up to date with the installation of active fire prevention and fire-resistance measures. Structural failure happened with the collapse of the steel perimeter columns and the oor slabs collapsing as this edge support was taken away. The massive concrete transfer slab at the 20th oor prevented further progressive failure. The Concrete Centre is funding further research into the behaviour of the tower's concrete structure at the University of Edinburgh.