At approximtly 20:51 Company 1 was alerted for a motor vehicle accident involving a Tractor Trailer at the 104.1 mm on interstate 95. Engine 1 marked enroute with 4 Squad 1 also marked enroute with 5. The engine arrived on scene to find a single vehicle underneath the rear of the Trailer with extensive damage. The driver didn't suffer any injuries. Medic 227 obtained a patient refusal. Squad 1 shortly returned to service. The engine remained on scene for a extended period of time.