AMSTERDAM (Reuters) - Early one evening Helena van Gelder heard bricks falling. Minutes later, she and her three young sons were standing outside their 17th-century home, watching it sink eight inches within hours.
It was a terrible shock, but the family living on Amsterdam's Vijzelgracht thoroughfare was merely the latest casualty of a tunnel that has been the city's 3 billion euro ($4.5 billion) headache for seven years.
Years behind schedule and so over-budget officials have abandoned hope it can recoup the cost of construction, the new metro project is wrecking historic buildings as it cuts through spongy sand and water more than 30 metres below sea-level.
"Seven years of nuisance and this is what we get," said the 47-year old communication adviser. "I truly find it terrible. I am not the sensitive type, but I don't want to be near that house any more."
Built to house a rapid transit system aimed at connecting business in the north and south of the city and relieving overcrowding, for now the subway is a gash through the city and risks joining history's great construction fiascos.
No-one has died in the project so far, unlike the 195 killed during construction of the Hoosac tunnel in Massachussetts before it finally opened in 1876 -- at a cost seven times original estimates, according to the North Adams Public Library.
The Dutch project's cost is still less than the estimated 10 billion pounds poured in the 1990s into the Channel Tunnel between Britain and the European continent -- that was double the original estimate.
But the scale of ambition -- driving an underground project beneath listed historic buildings through soggy marshland -- is comparable. And the nuisance is mounting.
Former Amsterdam city alderman Tjeerd Herrema resigned earlier this year in frustration at the project.
None of the companies involved would testify in public to the committee, but Herrema told a parliamentary committee last month the city had deliberately underestimated the costs to win backing when parliament approved it in 2002.
This was the reality that welcomed him to office in 2006. "Many times I have cursed this decision," Herrema said.
Estimates already have the North-South line running at a future loss. The 2 billion euros the new metro is expected to yield to the city in its 100-year lifetime falls short of its 3 billion euro construction cost.
Explaining the string of accidents, deadline extensions and budget overruns, Amsterdam mayor Job Cohen blamed business after a government commission in June ruled construction had literally reached the point of no return.
"We all are just amateurs in this perspective and we have to rely on professionals," Cohen told the commission. He has been in office since 2001 but polls show he remains popular.
Resident Van Gelder has been living in a temporary home for a year since water leaking from the site undermined her building: about 10 more historic buildings nearby are on the verge of collapse.
Costs incurred so far on the tunnel already total 1.1 billion euros or 1,419 euros per resident: an additional 600 million would have to be paid in fees if contracts were canceled and the tunnel abandoned, the June commission headed by former Agricultural Minister Cees Veerman concluded.
The tunnel is the ninth to be drilled in the Netherlands and will connect travellers faster to the business and legal district where banks such as Royal Bank of Scotland, ABN AMRO and ING are based.
Even though the new underground railway won't open for another eight years, engineers point out it is just one of a handful of similarly problematic projects in Europe.
Archeological findings during construction have caused delays in Rome's new subway of 31 underground stations. In Cologne, two people died in March after the city archive collapsed as a result of construction on the metro.
Madrid has since 2007 been working on an extension of its metro network by 75 km by 2012 and Paris wants to add 7.5 km to its underground network: all the projects face delays or cost overruns.
"It is almost systematic that the costs are underestimated for metro systems," said Jack Short, chief of the International Transport Forum (ITF), a global platform for transport, logistics and mobility, which is part of the OECD.
"We definitely have seen a tendency of what you might call 'project optimism'," Short said, attributing this to the prestige involved in such projects.
"They have to make the numbers look good, the revenues a bit higher and the costs a little bit lower than what they really are."
Working through marshland, the Amsterdam project has also faced unique challenges. Buildings in the city stand on long pilings -- literally, wooden or concrete stilts sunk at least 10 metres below ground.
They present a special difficulty in building a 9.7 km subway through sand. The tunnels avoid the pilings, instead following the meandering street pattern.
One of the main challenges of tunneling through sand is the need to fight back the pressure of water below the surface, said Peter Dijk, project director of the North-South line.
"When you are drilling somewhere in the Swiss mountains, you don't have slack ground and water, so you don't need counter- pressure," Dijk said.
Inside the cavernous hole where the North-South subway line will connect with the city's central station, huge slabs of concrete hold back sand and water, while enormous excavators use the future station's space to prepare for digs.
Notwithstanding, the project has also been badly handled.
Dijk took over the project amid bickering between city officials and project managers. New city alderman Hans Gerson was recently given responsibility for the project, and vowed to see its completion after his predecessor stepped down.
"The tragedy is that with the construction of relatively simple dam walls, simply bad work has been delivered, not because it is such a difficult job," said Gerson in his office, surrounded by pictures of the construction.
It was only in June that the city council approved the drilling of a section beneath the city's historic center which dates back to the late 12th century in the swampy delta of the Amstel River.
Ultimately, said the ITF's Short, such headaches are a symptom of growth and progress, the like of which will challenge more and more cities worldwide in a growing world.
"Lots of places have been in the dilemma of Amsterdam," he said. "Do we keep going, do we go backwards?"
Additional reporting by Jijo Jacob and Carl Bagh in Bangalore; Editing by Sara Ledwith