In November 2011 a five month old baby diseased after being hit by a loud-speaker that fell from the ceiling of a swimming pool in Tilburg, The Netherlands. Over the past decennia several incidents occurred in swimming pools worldwide due to false ceilings that fell down. Chlorine stress corrosion cracking of stainless steel supports was identified as the cause of failure. When water that condenses on the supports evaporates again, droplets of highly concentrated chlorine solutions are left behind. These chlorine concentrations, combined with temperatures of 35 to 50°C in the upper regions of the swimming pool and the tensions to which the supports are subjected, are an ideal combination to initiate stress corrosion cracking of stainless steel. In most cases the envisaged solution was to replace the stainless steel supports by supports made of other materials, yet the fatal accident in Tilburg shows that this is not yet a common practice everywhere.
Image courtesy of Orin Zebest, CC BY-SA 2.0
