While the ITC was being driven down the decline the tyre fell from the forks and started rolling.

It hit the back of a popping rig that was tramming down the decline before continuing to roll for about 500m.

The regulator said workers should ensure loads were adequately secured to prevent unplanned movement.

That can be done using slings, support cradles or jigs.

Documented procedures should also be supplied to workers, with supervisors to ensure the correct processes are followed.