A massive pipe rupture has sent sewage spilling into the Potomac River. The spill is turning part of the river gray upriver of Washington D.C. The utility, DC Water, says they are rushing to divert sewage around the rupture. The spill started on Monday. Officials say people should stay away from the area. Witnesses describe a horrific smell and sewage bursting out of the ground. The spill is not a threat to public drinking water, the utility said.