Under an open-perils (all-risk) property form, a loss is covered:

解析

An open-perils form covers any cause of loss that is not specifically excluded, so the insurer must prove an exclusion applies to deny a claim. This is broader than a named-perils form, which covers only the perils listed and requires the insured to prove the loss came from a named peril. Open-perils coverage generally costs more because it is broader.