Fires in History: Windsor High-rise

Windsor high-rise

When a 32-story high-rise in the center of the financial district quickly turned into a towering inferno, it showed just how important fire protection truly is.  As it so happened, that building was undergoing an extensive fire protection renovation that had not yet been completed.  The fire caused $72 million in damage to the building.  Fire sprinklers reduce property damage by 70% on average and extinguish the fire in less than half the time it takes for fire crews to arrive in many cases.  So, if the fire protection had been completed, it is fair to say the outcome would likely have been different.

The Scene

In 1979, the eighth tallest skyscraper was built in Madrid, Spain within the financial center of the city.  The Windsor Tower boasted 106 meters and 32 floors.  At the time it was built, fire protection measures were lacking, so, to meet new building code, the Windsor was undergoing fire protection upgrades on February 12, 2005, when a fire detected on the 21st floor destroyed the building.

The 32-story concrete building with reinforced concrete core had a two-way spanning 280 MM waffle slab supported by the concrete core, internal RC columns with additional 360 MM deep steel I-beams, and steel perimeter columns.  Floor by floor, fire protection was being added to the building, starting at the bottom floor.  The three year project included fire protection to the perimeter steel columns using a boarding system, fire protection to the internal steel beams using a spray protection, a sprinkler system, and a new aluminum cladding system.  At the time of the fire, the fire protection for all floors below the seventeenth were close to complete, except floors 9 and 15.  The gaps between the cladding and the floor slabs had to be sealed with fireproof materials still.  In addition, the fire stopping to voids and fire doors to vertical shafts were not fully installed and the fire sprinklers were just beginning to be installed.

The building was adopting an open floor plan concept, so fire compartmentation could only be done floor by floor.  Vertical compartmentation couldn’t fully be achieved because of the lack of firestop systems in floor openings and between the original cladding and floor slabs.

The Fire

The fire started on the 21st floor of the Windsor Tower at midnight.  It spread quickly, first driving up to the 32ndfloor and then traveling down to the 2nd floor – all within 1 hour.  With no fire stops yet installed, the fire easily devoured the building. 

Firefighters arrived soon after midnight.  It took 24 hours to extinguish the blaze.  This fire was named the worst fire in Madrid’s history.    

The Aftermath

The fire was originally thought to have been started from an electrical short-circuit; however, police discovered that a door was forced open.  Additionally, amateur video footage shows what appears to be people moving throughout the eighth floor, below the fire.  Other video footage shows lights inside the building, after it was thought that the lights went out.  It is still unclear what the true cause of the fire was.

It took 24 hours to completely extinguish the fire.  The fire caused $72 million (pre-renovation) in damages.

Following the fire, it was determined that the following factors lead to the rapid growth of the fire:

·         Lack of effective firefighting measures, such as automatic fire sprinklers.

·         Open floor plan.

·         Failure of vertical compartmentation measures in the façade system and floor openings.

·         The fire protection on the existing steelworks below the 17th floor had been completed, except for the 9th and 15th floors.  When the fire moved to the unprotected floors, the columns buckled, but did not cause a collapse.

The Windsor Tower fire acts as an excellent example of why high-rise fire protection is an absolute necessity.  If the fire protection was completely installed at the time of the fire, it is likely that the fire would have been contained to the floor of origin, greatly reducing the amount of damage to the building.  

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