Boarding in the international airport in my city (western Canada), no container may be locked. I thought this applied to all flights everywhere.

Be sure and have ample insurance coverage for carried items, purchased from your insurance agent. I have this floater coverage on my cameras, etc., with each item described, and current valuation, in the policy description.

File a claim with the airline. In case of loss or damage, a record of the claim will be required by the insurer providing the floater.