By Mike Dunn

PHILADELPHIA (CBS) — A major milestone was reached today for the massive redevelopment project on East Market Street in center city:  concrete was being poured for the foundation of new retail and residential buildings covering the entire city block between 11th and 12th Streets.

Thirty-five cement mixers have begun pouring the 350 cubic yards of concrete for what is the first phase of the project titled simply “East Market.”

“East Market is a recreation of a full city block, from Market Street to Chestnut Street, 11th Street to 12th Street,” says Daniel Killinger, managing director of National Real Estate Development, the developer of the entire project.  “Today is the first concrete pour in our first phase.  The first phase will be about 100,000 square feet of retail, residential apartments, signage, and loading.”

The first phase, on the Market Street side, also will include about 190 parking spaces, below ground.

The original building opened in 1889, as Snellenberg’s Department Store.  Killinger says in its place will be two buildings to open next year.

“Each building will have two stories of retail,” he says, “and the building at the corner of 11th and Market Street will also have a 15-story tower with 322 residential units.”

One retailer has already signed up — Mom’s Organic Market will open next spring — and negotiations are underway for other stores.

Beyond that, Killinger says, the developers will remake Ludlow Street, just south of Market, and will build an office tower with 160,000 square feet:

“That will be the new center of this community, anchored with food and beverage, great new restaurants, boutique shops, and the entrance to our residential building and to our new office building, at 34 South 11th Street, which used to be the Family Court building,” he tells KYW Newsradio.

The final phase of the project will be on the Chestnut Street side, with work there possibly beginning as early as next year.