Occupational health and safety specialist

Cathy Calvin is the newly appointed occupational health and safety specialist for the local school board. She has just been told of an incident experienced by an employee in the administrative office. It seems that two employees were trying to move a full filing cabinet from one corner of the office to another. The cabinet tipped, crushing the foot of one of the employees. The office staff applied first aid and rushed the injured employee to the hospital. The employee will be off work for at least two weeks. Board policy requires a full investigation of any lost-time injury. As a relative newcomer to the health and safety role, Cathy has never conducted an incident investigation before.
Can you help Cathy design an appropriate strategy for approaching the investigation?
Provide recent reference from 2019-2022