Driving south on I95 under normal condition. After driving for about a hour truck started smoking under the hood. I pulled over and turned off vehicle. I released the latch to open hood. When I got out of the vehicle to lift the hood there were flames coming from both sides of the hood. I did not lift the hood. I moved away from the vehicle and called 911. Police and fire department responded and extinguished the fire. Vehicle was a total loss. GM indicates they will not investigate the cause and I should work through my insurance company for compensation.