A raging fire spewing fist-sized embers engulfed much of an iconic Jersey shore boardwalk Thursday, destroying more than 50 businesses and undoing months of rebuilding efforts after the inundation of Superstorm Sandy. Workers joined the fire in tearing into the boardwalk a last-ditch effort to rob the inferno of fuel that helped preserve what was left of the economic lifeblood of Seaside Park and Seaside Heights. The wind-whipped fire devoured eight blocks of boardwalk four in each town and caused millions of dollars in damage before workers halted its advance by ripping out a large section of boardwalk and piling up huge makeshift sand dunes meant to hold back fire, not water.