Hammersmith Bridge in danger of imminent collapse, three others undergoing repair

The much-loved classic nursery rhyme 'London Bridge is falling down' is on the brink of having a modern re-write.

London's Hammersmith Bridge is in danger of imminent collapse and three others are undergoing urgent repairs.

The 133-year-old cast-iron structure has been neglected for decades, and after cracks were discovered in vital areas it was closed to all traffic, including pedestrians, last month.

The closure meant that the 10-minute walk to school for William Blackshaw, whose mum is a Kiwi, now takes 40 minutes through a dodgy, unlit park.

"I just feel really angry as well as scared because I feel like I'm just not going to be able to do it," Blackshaw says.

Franc Vissers, from Taranaki, is also concerned his local Thames River crossing is in imminent danger of falling down.

"It could collapse at any second. A bit of heat and some wind and it could fall over right behind us."

Hammersmith Bridge is so unsafe that boats aren't even allowed to pass under it.

"This is the place where the Oxford-Cambridge boat race goes under. That won't happen this year. There are rowing clubs all around here who can't use it. No one can go underneath," Vissers said.

It will cost a quarter of a billion dollars to fix the bridge. That's too expensive for the local councils, London's transport operator TfL, and the UK government - no one is willing to pay for it.

And that's not the only London bridge that is crumbling.

Vauxhall Bridge and Waterloo Bridge are closed to car traffic while they receive structural repairs, meaning only buses and pedestrians can use it.

Last month, London Tower Bridge broke down, with its moving deck stuck open for more than an hour, creating even more commuter chaos.

London's bridges: Once just a nursery rhyme, and now a news headline.