A 30-inch water main broke early this morning in the city's Kensington section spilling tens of thousands of gallons into residential basements and leaving a yawning crater in the middle of the road.

The cast iron pipe erupted about 1:30 a.m. on the 2100 block of 4th Street, said Laura Copeland, spokeswoman for the Philadelphia Water Department.

"We're still assessing the damage," Copeland said. "We don't know what caused it."

The water flooded the basements of thirteen homes. A crew of eight plumbers worked this morning to replace nearly a dozen water heaters and furnaces destroyed by the flooding.

"We want to get those all replaced today," Copeland said. She said the gaping sinkhole created by the rupture will take much longer to repair - up to a week.

The Streets Department diverted traffic near the site, about a block from McKinley Elementary School. Susquehanna Avenue is closed from American to 5th Streets, and 4th Street is closed from Diamond to Susquehanna.

At the intersection of North 4th and Susquehanna Streets, Victor Bouloge, 23, and his wife, Milagras Garcis, 40, lamented the damage the flood caused to their home, which had about three to four feet of water in the basement.

Their washing machine was tilted, a computer and its monitor along with a television set was destroyed.

"The water was cold," said Bouloge. "We lost everything down there. The washing machine, dryer, computer, clothes."

Bouloge said the family was without heat or gas for "awhile" as the water department and other city agencies work to repair the break.

Garcis said her husband called the water department last night about 7 p.m. when they noticed a "leak in the road." She said water department employees inspected the intersection but it was unclear what, if any, repairs they made.

"There was a small leak, it wasn't that big," Garcis said.

This morning, a hole took up at least half of the intersection.

Workers from Philadelphia Gas Works and other city agencies are at the site.

Contact staff writer Sam Wood at 215-854-2796 or at samwood@phillynews.com.