As a general principle, the onus of showing that a loss has occurred which was proximately caused by an insured peril rests on the assured. Taking a fire policy as an example, once an insured who has established a loss by fire is prima facie entitled to recover. It is then for the insurer to establish that the fire was started with the insured's connivance in order to reject the insurance liability.1 The evidence may show that the loss is prima facie covered by the policy, but if the matter is litigated, the burden of proof still rests upon the assured.2 Where the cause of a past event is in issue and two or more competing causes are advanced, the burden of proof on causation remains on the claimant throughout, and though the defendant can advance a competing cause, there is no obligation on the defendant to prove its case.3 The insurer may elect to put the claimant to proof rather than advance a case.