A busy block of Walnut Street in Center City could remain closed for days as crews work to clean up a broken water main.

The block - between 16th and 17th Streets - is home to retailers such as BCBG, American Apparel and the Apple Store that have been busy during the holiday shopping season.

The stores are still open, but visitors will have to park on another block and may find traffic in the area even worse than usual.

A Philadelphia Water Department spokeswoman said the 12-inch water main broke around 4:30 p.m. Saturday, cutting off water service to at least 20 businesses and residents.

"We had the main back in service around 9:30 [Sunday] morning," PWD spokeswoman Laura Copeland said.

The next step, she said, is for PECO and Philadelphia Gas Works crews to check the area for any damaged infrastructure.

After that, the Streets Department will repave the area and open the block. Copeland said it's unclear how long the street will be closed.