A water main break disrupted the dinner hour and retailers on bustling Walnut Street, one of the toniest shopping districts in the city during the height of the holiday season.

The main shopping district in Rittenhouse Square was flooded late Saturday afternoon after a water main break sent water gushing up through several large fissures in the middle of the 1600 block of Walnut Street.

Asphalt was pushed up by the water in front of the busy Apple store, and most of that block was under as much as eight inches of water, sending streams down other blocks in all directions.

A sales representative at the Apple store, at 1607 Walnut, who answered the telephone said, "We are closed due to an unforeseen event. Unfortunately, there is a water line break, so the police have shut down Walnut Street."

At about 9:30 p.m. the 12-inch main was shut down and a city crew would be working through the night, said Laura Copeland,spokeswoman for the Philadelphia Water Department.

Copeland said that closing of the main left 20 to 25 residential and commercial customers without water service until the main is repaired.

Streets were closed between Locust and Chancellor on 16th Street, and on Walnut Street between 15th and 17th Streets, Copeland said.

A Starbucks employee at 16th and Walnut said the store was closed and would not reopen until morning.

"We are just waiting to hear back from police and the water company. Everything is blocked off; no one can walk in." Water continued to flow at 6:30 p.m. "We are technically still open, but just no customers," the worker said.

"We're closing up, cleaning up," said James Reynolds, general manager of Qdoba Mexican Grill at 1528 Walnut, shortly before 7 p.m. "We're open, but you can't get to us. The water has been shut off, but we have some in the pipes," he said.

At the swank Le Bec-Fin restaurant, Shannon Corin, private events coordinator, said, "We've had some guests who have had difficulty getting to us, but we are open and serving dinner. We have a wedding reception going on right now in our private dining room, and some very happy diners throughout the restaurant."

Corin said police were letting people through. "The sidewalks are still open." Le Bec-Fin still had water. "We are able to wash our dishes."

Contact staff writer Linda Loyd at 215-854-2831 or lloyd@phillynews.com.

Staff writer Peter Dobrin contributed to this article.