At what point are serious injuries which occur on a job site required to be...

Under the Alberta Occupational Health and Safety (OHS) Act, employers have a strict, legal obligation to report specific "serious incidents" to the government (Alberta Labour / OHS regulatory body) immediately, or as soon as practically possible. This rapid reporting requirement allows OHS officers to secure the site, conduct an independent investigation, and prevent further immediate harm. The legislation specifically defines what constitutes a reportable serious injury. It explicitly states that an incident must be reported if it results in an injury that requires a worker to be "admitted to a hospital as an inpatient." There is no waiting period to see if the employee stays for two days (Option C) or a week (Option B). The trigger for the legal reporting requirement is the moment the medical facility formally admits the injured worker as an inpatient. Failure to report such an incident immediately is an offense under the OHS Act and can result in severe legal penalties for the employer and supervisors.