BOSTON (CBS) – The hole in the ground that was once Filene’s Basement is no more after workers began burying the space under the largest pour of concrete in the city’s history.

The Millennium Tower is being built on the former site of Filene's. (WBZ-TV)

The Millennium Tower is being built on the former site of Filene’s. (WBZ-TV)

The work being done by Suffolk Construction began early Saturday morning is an important milestone in the construction of the $689 million, 1.4 million-square-foot Millennium Tower/Burnham Building development in Downtown Crossing at the former site of Filene’s Department Store.

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WBZ NewsRadio 1030’s Kim Tunnicliffe reports

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The new, 60-story mixed-use tower will reach 625 feet and include condos, offices and retail space. It will take 600 trucks about 36 hours to pour 6,000 cubic yards of concrete to create the slab for the new building.

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