When the owners of 3 adjacent homes on 8th Avenue in Clearwater Crossing, Alberta first consulted counsel in 2023 about their losses, they arrived with photographs of scorched foundations, insurance correspondence, and a shared conviction that the residential rental property next door was the source of the fire that destroyed their homes. What they did not bring—and what no amount of investigation could recover—was physical evidence capable of identifying how the fire started, where precisely it originated within the rental property's structure, or which specific act or omission by the property owner caused the ignition. The 35 km/h winds that drove the flames through all 4 structures ensured that by the time the local volunteer fire brigade controlled the scene, the evidentiary foundation for any negligence claim had been reduced to ash alongside the buildings themselves. This lesson examines how Alberta law applies the balance of probabilities standard to claims where circumstantial evidence must substitute for direct proof of causation, and why that standard ultimately determines whether the neighbouring property owners can succeed against the landlord who owned the rental dwelling.
The balance of probabilities is the civil standard of proof throughout Canadian common law provinces, including Alberta. It requires a claimant to establish that the existence of a fact is more probable than its non-existence—a threshold sometimes expressed as proving that something is more likely than not, or that there is a greater than 50 percent probability that the asserted fact is true. This standard applies to every element of a negligence claim: the existence of a duty of care, breach of that duty, factual causation, remoteness, and damages. A claimant who proves duty, breach, and damages but falls short on causation has not made out a claim in negligence, regardless of how sympathetic the circumstances or how substantial the losses. The standard is neither criminal proof beyond a reasonable doubt nor mere suspicion or speculation; it occupies a middle ground that demands persuasive evidence while acknowledging that absolute certainty is neither attainable nor required in civil disputes. Understanding how this standard interacts with circumstantial evidence in fire claims is essential for anyone managing, adjusting, or litigating property damage claims where the origin structure has been completely destroyed.