“The carelessness or mere failure which constitutes ordinary negligence, changes in gross negligence to an indifference to, and blatant violation of a workplace duty. Gross negligence can be described as a conscious and voluntary disregard of the need to use reasonable care, which has or is likely to cause foreseeable grave injury or harm to persons, property or both. It is conduct that is extreme when compared to ordinary negligence. Gross negligence also focuses on the magnitude of the risks involved, such that, if more than ordinary care is not taken, a serious mishap is likely to occur. Ordinary negligence and gross negligence accordingly differ in degree of consciousness or inattention; and both differ from ‘wilful misconduct’, which is conduct that is reasonably calculated to cause damage or injury.”