Hardrock had been hired by subcontractor Stresscon to place concrete girders, which Stresscon was supplying to lead contractor Mortenson Construction. Hardrock was using a crane to lift one of the panels when the crane’s rigging snagged on a girder, sending the panel falling on workers below.

An OSHA report found that Hardrock workers hadn’t been properly trained to watch the crane’s rigging throughout the lift. Normally, the US safety inspector would fine up to $5,000 in cases like this. However, as Hardrock is a small firm, and this was its first violation, the fine was reduced to $1,500.

Hardrock has until Wednesday 23 January to contest the finding.