(Warwick, RI) -- The Rhode Island Department of Environmental Management is announcing the emergency closure of Upper Narragansett Bay to shellfishing because of a collapsed sewer line. The DEM says the Warwick Sewer Authority discovered on Sunday that an estimated three-hundred-thousand gallons of sewage overflowed into a brook which empties into the bay. Any shellfish that was harvested near the outlet of Old Mill Creek in Warwick after 10:30 a.m. yesterday should not be consumed. Health officials are also announcing the closure of Conimicut Beach in Warwick in connection with the incident.