A fire occurred in the funnel of a fishing vessel in the vicinity of the exhaust mufflers/silencers. The Plaintiff owners alleged that during repairs to the vessel’s exhaust system the Defendants had installed an inadequate gasket and had not allowed for expansion and contraction in the system. The issue in the case was the origin of the fire. The Plaintiffs’ expert said that the leaking exhaust gasses due to the faulty repair ignited unburned hydrocarbons in the exhaust gasses. The Defendants’ expert said that the source of ignition was diesel fuel spilled from a fuel tank vent line that terminated inside the funnel. The Court held that the Plaintiffs, who had the burden of proving the cause of the fire, had failed to show conditions under which the exhaust gasses could have ignited. They also failed to show that soot which had built up in the funnel could have ignited. The Court did not accept that the Defendants’ theory of a fuel spill from the vent line had been proven either but, as the Plaintiffs carried the burden of proof, the claim failed.