City officials urged residents to boil drinking and cooking water for 24 hours. Bacteria tests were being conducted at water-treatment plants in the city and county to ensure that water was safe for consumption. Such tests are required by the U.S. Environmental Protection Agency.
Service was restored at about noon, about nine hours after the break, said Scott Huff, the city's water superintendent.
"We probably lost a million and a half gallons of water," he said. "We lost all of the reserve water in our six tanks."
Mr. Huff estimated that at least 10,000 residents were without water for several hours.
The 50-year-old main apparently broke shortly before 3 a.m. Water pressure began noticeably dropping at Big Creek Water Plant, off the Lincolnton Highway, according to George Nichols, the water services director.
At Shaw Industries, about 150 workers were told to go home after the loss of water interrupted production, plant manager Vince Shivers said.
"We lost tens and tens of thousands of dollars in productivity," he said. "As a plant that relies so heavily on the use of electricity, water and natural gas, the loss of one of these types of utilities is vital to our daily operations."
Mr. Shivers estimated that the plant, which uses about a million gallons of water a week, lost a quarter of a million pounds of fiber used in the creation of carpets and rugs.
Water and steam are used to operate much of the machinery at the plant, said Patrick Blewett, a plant engineer.