Why do London's pavements keep exploding?

IN THE LAST FEW YEARS, our pavements have been erupting into fireballs that have sent pedestrians running for cover amid flames and flying chunks of concrete. Just last month, an electrical manhole explosion in Blackfriars caused a fire that took nearly an hour to extinguish and left a passer-by being treated for burns. But why? According to Dr Taku Fujiyama, senior lecturer in civil, environmental and geomatic engineering at UCL, water is to blame. Yep, you might think H2O is your buddy, what with its handiness for stopping you from dying of thirst, but apparently not.

‘Water’s like our dangerous friend!’ says Fujiyama. ‘When there’s heavy rain, it can drag earth with it, which can put pressure on underground gas pipes and make them leak.’ A lot of the old gas pipes are ‘poorly maintained’ anyway, also causing leaks; the same is true of our water pipes, whose leaks cause even more earth to move and more gas pipes to rupture.'

Now that the water and sewer pipes are ageing, we’ll get more exploding pavements,’ explains Fujiyama. ‘Though it isn’t just exploding pavements.’ No? ‘Sometimes massive sinkholes will open up too.’ Great!