Final answer:
A theatre could be held liable under the Occupational Health and Safety Act for failing to maintain the stage in good condition, as it is required to ensure a safe working environment for its employees.
Step-by-step explanation:
If a theatre fails to maintain its stage in a better condition, they could be liable under the Occupational Health and Safety Act (OHSA). This legislation is designed to protect workers from health and safety hazards at their place of employment. It includes requirements for employers to provide a safe working environment and to inform employees about any potential dangers that could affect their safety. OHSA would hold the theatre accountable for any negligence in maintaining the stage that could lead to workplace injuries or accidents.