A Harwich firefighter is being credited with rescuing a woman from a vehicle after a single-vehicle crash in Dennis, according to a post on the department’s Facebook page. Fire officials say slippery roads led to multiple accident on Route 6 from Bass River to Exit 82. Ambulance 74 was returning from a previous call when the crew came across a crash in the median that left the motorist stranded in a large puddle of water. That’s when firefighter Andrew Riker assisted the uninjured driver from her vehicle.