One year after a deadly biogas plant collapse in Flemløse killed three people and seriously injured six, new documents reveal that engineers were warned minutes before the accident that something was wrong. Labor authorities now point to a series of serious engineering miscalculations and missing safety checks.
Warnings Ignored Before Fatal Collapse
Just moments before the roof of a biogas silo in Flemløse gave way in late November last year, a photo message warning about bending steel plates was sent to the lead engineer, Gerhard Moser, in Austria. The incident killed three workers and injured six others.
According to Denmark’s Labor Inspection Authority, Moser’s firm failed to account for crucial structural weaknesses in its calculations. The engineer responded that the added concrete load would not make a difference since only a small amount remained to be poured. Yet, investigators later determined the deformation of plates and bolts clearly showed the structure was at risk.
Fatal Errors in Structural Design
The investigation found extensive flaws in the static design calculations. Inspectors concluded the steel joints, bolts, and nuts could not bear the weight of the wet concrete. There were also indications that the supporting beams were drilled with holes that weakened them.
Adding to the instability, the structure had never been properly fastened to the concrete silo rim, which was essential to its strength. Authorities said Moser should have verified the installation during an inspection three days before the collapse, but he participated only through a video call while working on another project in the Netherlands.
A subsequent audit found that the required cross-bracing on top of the structure was missing. The overall project documentation also lacked clear standards and design norms. None of Moser’s calculations had been independently reviewed by another engineer, as required by safety protocols in Denmark, a country known for strict oversight of public and industrial construction, from bridges to agricultural innovation.
Disputes Among the Companies
Three international contractors were involved: Formtec from Germany, Envitec from Germany, and Bio Dynamics from Belgium. Moser’s engineering company supplied the design documentation. After the tragedy, the Danish Labor Authority alerted authorities in Germany and the Netherlands, noting similar projects were underway in those countries.
In October 2025, Moser sent his comments denying any responsibility. He claimed his role was limited to delivering structural calculations and insisted his firm bore no liability. Three weeks later, Formtec Spezialschalung also received an official reprimand. Testing by VITA Engineers and Force Technology found the used steel components insufficiently strong. Formtec rejected these findings, arguing that the tests were inconclusive.
Ongoing Legal Disputes
Both Formtec and Bio Dynamics have filed complaints to Denmark’s Working Environment Appeals Board. Formtec disputes the claim that it failed to provide Bio Dynamics with proper operating instructions for installing the formwork. Bio Dynamics challenges emergency orders from April requiring the company to prevent structural collapse risks and to ensure safer installation procedures.
The appeals body has confirmed it is currently handling one case from each company. Earlier, it upheld a December 2024 order forcing Formtec to secure and verify the safety of its concrete form structure before use. Although more than a year has passed since the disaster, no one has been charged criminally.
Safety consultants, including union representatives, emphasize that detailed and fair investigations take time. They believe accountability matters most when it is based on comprehensive evidence, not speed.
Future of the Biogas Facility
Since the collapse, inspectors have conducted several follow-ups at the Flemløse site but found no new safety violations. Construction has resumed under stricter supervision. The biogas plant, located in central Funen, is now expected to begin operation on February 1, 2026, following a complete redesign of its upper structures.
Even so, the tragedy remains a somber reminder of how technical shortcuts can have fatal consequences. The case highlights the importance of independent engineering review and workplace safety culture, topics central not only in Denmark’s construction projects but also across its growing renewable energy and engineering community.
Sources and References
The Danish Dream: Danish Farmers Use Virtual Fences for Cattle
The Danish Dream: Best Engineers in Denmark for Foreigners
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