Dec 31 (Reuters) - A massive spill of raw sewage in California on Friday forced the city of Long Beach to close all swimming areas at nearby beaches, officials said. Between 2 million and 4 million gallons (7.6 million to 15 million liters) of raw sewage leaked into the Dominguez Channel, which empties into the Los Angeles harbor, it was discovered on Thursday, according to a press release from the City of Long Beach. The leak occurred in the city of Carson and was caused by the failure of a 48-inch sewer main line, the release stated. It was not immediately clear why the line failed. City water quality teams from Long Beach are testing the level of pollutants in the affected areas, which includes 7 miles (11 km) of beaches. Swimming in the waters will remain prohibited until the amounts of pollution return to within normal levels. Tourists in the area for New Year"s celebrations were disappointed with the news. "You come all this way and you don"t get to play in the sand or the ocean? That doesn"t seem fair," Sandi Williams, who had traveled from suburban Massachusetts, told the Los Angeles Times. "We were so looking forward to this change in scenery, but like everywhere, there"s catastrophe."