Streets are closed again around Philadelphia's Rittenhouse Square after a second section of a water main broke early Thursday morning on 18th Street near Locust.

About 5 a.m., a 10-foot section of main broke a little farther north from a different section that broke Wednesday morning, said John DiGiulio, a spokesman for the Philadelphia Water Department.

Water was "escaping out onto the street" for about half an hour to an hour before it was turned off, DiGiulio said.

Two streets around the square — 18th Street on the east side, from Spruce to Walnut, and Rittenhouse from 18th to 19th Street — remain closed, DiGiulio said early Thursday afternoon.

The restaurants Parc and Devon, both on 18th near Locust, were closed Wednesday night through Thursday afternoon because of the breaks. Both restaurants were hoping to re-open for Thursday night's dinner.

Thursday's break did not occur on the same section that broke Wednesday, DiGiulio said.

It was late Wednesday morning when a six-foot section of the pipe, also on 18th Street near Locust broke, clogging traffic around the Square and causing flooding damage at the Curtis Institute of Music's historic Locust Street building.

Wednesday's break flooded the basement and subbasement of the Curtis building at 1726 Locust. There appeared to be extensive damage to those two levels, which includes a workshop for repairing and maintaining pianos. Between 15 and 20 pianos were in the workshop at the time, and a total of three organs were in the affected area. Wednesday was the last day of school before winter break, and classes don't resume until Jan. 16.

Jennifer Kallend, a spokeswoman for the Curtis Institute, said that with Thursday's second water-main break, the basement and subbasement flooded again. "The immediate effect is that the cleanup work that we started yesterday needs to begin all over again," she said. She said Curtis is still assessing the extent of the damage.

DiGiulio said the Water Department is hoping to repair the second break by early evening Thursday. The age of the main and the colder weather are believed to be contributing factors in both breaks, he said.