Rescue Squad 14 (SQ814) responded to the second extrication of the day at 1349 hours.  The squad arrived at the innerloop of I-495 at Kenilworth Avenue to find one trapped in a vehicle that was struck by a dump truck.  The squad crew removed two doors and the roof to provide patient access.  The patient was quickly extricated and transported to a local trauma center.  Rescue Squad 14 was ready for service at 1432 hours.