It would appear that you would have a case of negligence on the driver of the pickup for not tying down or otherwise securing the items in the bed of the truck. Hopefully you were able to get the driver of the truck to stop and exchange information with you so that you could place a claim against them.

If not but you got their license plate then you may want to contact local law enforcement to see what steps you would have to take to find out the owner of the truck to contact them, if a report must be made, etc.

You are correct if their insurance company does not find their truck driver to be liable or negligence or if the other driver cannot be found/identified then you would need to place a claim through your own physical damage coverage and pay a deductible.

Another option would to be to take the person to court and hope to get a judgment against them for the amount of the damages to your vehicle that the box spring caused when it fell off of their truck.

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