The 6-inch, cast-iron pipe broke around midnight on West 11th Street between York and Cutter streets, said Walter Pease, the city's director of water utilities.
About 15 homes lost water service but were expected to be back in service by shortly after 9 a.m. once repairs to the pipe were completed, Pease said.
No houses were damaged by flooding from the main break, which caused a hole about 3 feet deep in the roadway, according to Pease.
