Companies fined total of $400,000 in London, Ont., construction collapse that killed two workers

Two workers pouring concrete on an interior floor. Photo: Matt/Adobe Stock

Two companies have been fined a total of $400,000 after two workers were killed and four others critically injured when a section of a building under construction in London, Ont., collapsed.

The incident happened on Dec. 11, 2020, when the building collapsed to the ground floor during a fourth-floor roof level concrete pour.

iSpan Systems LP fabricated the building’s structural steel frame, including the frames necessary to support the concrete forms. East Elgin Concrete Forming Ltd. was responsible for the concrete pour, retaining supervisory duties while subcontracting the roof pour to another company.

A Ministry of Labour, Immigration, Training and Skills Development (MLITSD) investigation identified deficiencies in iSpan’s fabrication and methodological errors in East Elgin’s procedures that contributed to the collapse.

East Elgin employed a laser level and directed the subcontractor to pour to the height of the laser level. The laser level on its own failed to account for the deflection of the steel frame that occurred from the weight of the concrete. The use of a dipstick would have remedied this problem by providing a true reading of concrete depth during the deflection process.

As a result, workers were left with the incorrect assumption that the concrete depth was insufficient at certain locations in the pour. Consequently, more concrete was applied than had been specified by iSpan.

An engineering analysis carried out by MLITSD engineers determined that the concrete placed exceeded the design values by considerable amounts. The weight of the applied concrete contributed to the collapse and/or its severity.

Good engineering practice requires not only that a building possess sufficient capacity to support anticipated loads, but also that it possess a margin of safety for unexpected loads.

The MLITSD engineering analysis determined that another contributing cause of the collapse was the failure of a roof beam support, referred to as a beam pocket. The loads transferred to this beam pocket from the stud packs exceeded its ultimate load carrying capacity resulting in the failure.

The analysis revealed that while iSpan’s approved engineering drawings specified a 14-gauge deep track for the stud pack, an iSpan employee changed the deep track to a thinner and shorter 16-gauge shallow track. Additionally, the welds between the studs were placed lower than had been specified by the fabrication drawings which may again have reduced its capacity.

iSpan’s quality control department failed to detect these errors.

If the wall had been fabricated as designed, it would have possessed a sufficient margin of safety to account for the overpouring of concrete and the collapse could have been avoided.

iSpan failed, as an employer, to ensure that a building, structure or any part thereof, or any other part of a workplace, whether temporary or permanent, was capable of supporting any loads that may be applied to it in accordance with good engineering practice, contrary to section 25(1)(e)(iii) of the Occupational Health and Safety Act.

East Elgin failed, as an employer, to provide proper information, instruction and supervision to a worker to protect the health and safety of a worker, contrary to section 25(2)(a) of the Occupational Health and Safety Act.

Following guilty pleas in the Ontario Court of Justice, iSpan Systems LP was fined $260,000 and East Elgin Concrete Forming Ltd. was fined $140,000. The court also imposed a 25 per cent victim fine surcharge as required by the Provincial Offences Act. The surcharge is credited to a special provincial government fund to assist victims of crime.