WAREHAM, Mass. — Massachusetts authorities say an on-duty firefighter was struck by a hit-and-run driver and seriously injured while responding to a traffic incident during the powerful nor'easter.Wareham police say the Onset Fire Department firefighter was hit by a vehicle early Friday evening while at the scene of the traffic incident on Cranberry Highway, also known as routes 6 and 28.Officials have not released the firefighter's name or condition.