Category: Yorks & N.Midlands; E.Yorks & Lincs
An investigation by BBC ONE's Inside Out (Yorkshire and Lincolnshire) suggests that some developers may be underestimating the risks posed by unexploded wartime bombs in the race to rebuild the North of England's industrial cities.
Experts say piledrivers being used extensively in cities like Hull and Sheffield could set off 'lost' bombs buried since air raids in the Forties.
In the last decade, more than a dozen people have died in similar incidents on mainland Europe.
Magnetometers or ground penetrating radar can find buried bombs but they are expensive and many developers choose not to use them.
Bomb disposal contractor Mike Sainsbury told Inside Out: "We accept that at some point someone is going to hit a bomb with a drilling rig or a piling rig and there will be an incident.
"It is quite possible for a pile to strike a bomb and then cause it to detonate.
"Until there is an incident and someone is killed from striking an unexploded bomb (UXB) there won't be any real legislation or any real movement to make this work routine."
Inside Out researchers found documents that suggest an unexploded wartime bomb may be buried beneath a major new re-development in Hull.
Developers of The Boom - a £100m leisure and housing complex described in promotional literature as "an explosive experience in urban living" - were unaware of the documents, which were freely available in the local archives.
The company told Inside Out it was planning a survey to check the site and would carry out underground checks if necessary - but the programme found many developers had not checked the ground before piling.
Many sites are being redeveloped for only the second time since the war and most post-war building did not involve deep piling.
Because of the soft ground on the banks of the Humber Estuary, piles must be driven up to 16 metres to bedrock and bombs have been discovered up to eight metres below the surface.
Across the North Sea, screening sites in target areas is compulsory.
Rotterdam, which was heavily bombed by the Germans as well as the RAF and USAF, checks every site at taxpayers' expense.
City engineer Jauko Mutsaers said: "They were designed to kill people and they were designed to do damage... you can't determine if they are still active.
"One small shock might set them off. If you go into the ground with piles or you start moving the ground to make room for buildings... you might set off a bomb."
The developers of Hull's St Stephens Centre, ING, are based in the Netherlands but they told Inside Out they had not felt it necessary to carry out ground radar or magnetometer tests.
The company said a study of databases and historical records found there was a "low to moderate risk" of UXBs being present on the site.
They said workers were being warned of the possibility and were being told what to do if a suspicious object was found.
The company said half the piling work on the site - next door to Hull's main railway station - had already been completed without incident.
During the Blitz, one in ten German bombs did not go off and in one night bomb disposal crews in Hull had to deal with 400 duds.
It is believed that many which fell on existing bombsites were never found at the time.
Others were "abandoned" as too difficult to recover and left where they lay.
There is an official list held by the Army but the Ministry of Defence refused to release it to the BBC when Inside Out requested it under the Freedom of Information Act.
Inside Out was told there was no guarantee it was accurate and its publication may cause public concern.
Hull City Council said that as a result of the BBC's findings it would review its policies on the bomb risk.
Councillor Kath Lavery said: "There is a small risk but what you have to understand is that developers these days have to go through a process called due diligence both for themselves and for their funders... they are in fact well aware of these problems."
Inside Out will be broadcast on BBC ONE in Yorkshire and Lincolnshire on Monday 16 January at 7.30pm.
Notes to Editors
Please credit BBC Inside Out if any part of the above is used.
Inside Out (bbc.co.uk/insideout) is the name for the regional programme which is used across all the English Regions.