A four-alarm fire broke out at the Mandarin Hotel construction site this morning, and it was so strong that it shut down Boylston Street. The fire's origins have been located in "some cabinets on the fourth floor of the 15-story hotel," WBZ reports. The cabinets were part of a fitness room. WBZ has some scary footage of the smoke going up in the sky. Only one construction work sustained "minor burns." That's a true stroke......