Insurance company guidelines differ so you will need to check with your insurance provider to find out if your vehicle was covered for the accident which your friend was in since it does not sound as if he was on your policy. Even if your friend would normally be covered to drive your vehicle there may be an exclusion for criminal activity or if the driver runs from the police so that the truck would not be covered. Also since your friend was unlicensed this may make a difference on if your insurance carrier will pay out a claim or not.

Most carriers won't cover it if you didn't give permission to drive the vehicle.

If your physical damage collision coverage will cover the accident and your insurer declares your vehicle as a total loss, then they would normally give you actual cash value (ACV) for it. ACV is usually less than what you owe on a new car since as soon as you leave the dealership a vehicle depreciates.

If you owe more on your vehicle then the actual cash value that the insurance company will settle with you for, then you would need GAP insurance coverage to pay the difference between the ACV and the loan balance so that your truck would be paid off.