Explanation:

Operating expenses are those expenditures that a business incurs to engage in activities not directly associated with the production of goods or services. These expenditures are the same as selling, general and administrative expenses

Operating Expense = Salaries + Sales Commissions + Promotional & Advertising Cost + Rental Expense + Utilities

Operating Expense = Revenue – Operating Income – COGS

Loss of stock due to fire is not an operating expense. It is some sort of loss to business. So it is a form of non-operating expense.