The area is approximately 300-m from the Rhine River, and groundwater is very shallow. As noted in another NCE article, the contractor constructed 15 dewatering wells when only 4 were approved. Additionally, the pumping rate being used was 750 m^3/hr, or nearly double the 450 m^3/hr it was pumping in December of 2008. Clearly the groundwater is one component of the failure, but it does not appear that there is sufficient evidence to say exactly what role of the groundwater was or if the shoring walls did in fact fail and lead to the collapse of the Cologne historical archives and the deaths of two people.
On May 15 a drilled shaft rig operated by Mid America Drilling Corp was nearly swallowed by the 9-ft diameter hole it was drilling for a cell tower foundation near Harlan, Iowa. Fortunately nobody was injured and the truck did not suffer any significant damage.
In Arizona, the standard of practice is to use a temporary surface casing to prevent dangerous failures like that. I once saw pictures of a drilling contractor superindendent almost get sucked into a collapsing shaft, even with the temporary casing. Pretty scary stuff. Source: Harlan Tribune. (Photo by Samantha Bruck)