When the insurer that indemnified a post-secondary institution in Thornbury, Ontario for $340,000 in additional damage caused by unauthorized electrical work turns to recover that outlay, it does not pursue a single defendant down a single doctrinal path. The March 2024 incident left the institution's heritage administration building with fire-damaged wiring, smoke-contaminated ductwork, and a telecommunications switchroom that required complete reconstruction, all because an electrician employed by an insolvent electrical subcontractor energized circuits without authorization while a remediation contractor's project manager was absent from site. The regional telecommunications provider whose representative verbally approved the energization, the remediation contractor who held the prime contract and the statutory duty to supervise, and the post-secondary institution whose facilities staff failed to enforce its own hot-work protocols all occupy different positions in the causal chain, yet each may bear a share of the loss. Allocating liability among these parties in an Ontario subrogation proceeding demands a methodical application of the province's proportionate fault regime, careful attention to contractual risk-transfer provisions that may shift or cap exposure, and strategic choices about how and where to pursue each potential contributor when one of them has no assets to satisfy a judgment.
Ontario's approach to multi-defendant tort liability rests on the Negligence Act, which provides that where two or more persons are found at fault for the same damage, liability is apportioned between them according to the degree to which each is responsible. The statute abolishes the common-law bar that once prevented a plaintiff from recovering anything if it bore any contributory fault, and it replaces joint-and-several liability with a proportionate model for most claims. The subrogating insurer steps into the shoes of its insured and acquires no better rights than the insured possessed, which means that if the post-secondary institution's own negligence contributed to the loss, the recovery is reduced by the institution's share of fault. More significantly for practical recovery, each defendant is liable only for its own proportionate share; if one defendant is insolvent, the shortfall is not redistributed to the solvent defendants absent a statutory exception. The March 2024 loss therefore presents a stark arithmetic problem: the electrical subcontractor's insolvency eliminates a portion of the potential recovery, and the remaining pool of defendants must be large enough, and their proportionate shares must be high enough, to make the subrogation action worthwhile.