This is a graphic video of the danger of putting water on a grease fire.  You may want to add it to your fire prevention video collection. The article says the previous advice from fire prevention personnel to throw a damp tea-towel over a pan on fire was scrapped by the government in 2008 after fears it did more harm than good. A quick search of the internet provides many examples of where this advice is still the norm.    

http://www.walesonline.co.uk/news/wales-news/chip-pan-fires-what-chip-7021101