my place or yours – workmen on common property

As I sit and watch as one of my esteemed neighbours has workmen carrying out unapproved/unadvised renovations (has jackhammered the concrete slab – common property – this week) I wonder about our liability.  Not for the unapproved renos but because these workmen are on common property.  They are outside of this unit, in the open air and rain with their power tools, drop saws and angle grinders.  As I have noticed my many complacent neighbours just walk by with their blinkers on, I wonder if these workmen are injured – electrocuted or cut off a limb  – can they take action against the owners corporation?  Or can there be any liability to the OC if nothing is done or said to this owner?