GROUND WORKS on the World Trade Center Memorial in New York City began last month.
New Jersey contractor EE Cruz is installing 142 foundations in a year-long, $17M (£9M) contract for the memorial to those who died in the terrorist attacks of 11 September 2001.
The foundations will support two waterfalls in the spaces where the Twin Towers stood, as well as the memorial museum and visitor centre.
Building began in March with preliminary work on the original box beam columns to outline the perimeters of the Twin Towers.
Work halted in May amid disagreements over who would pay the soaring costs of the project.
A new design approved at the end of June reduced the memorial's underground space and construction restarted after the Port Authority of New York agreed to take responsibility for the project and committed £207M towards its costs.
The World Trade Center Memorial Foundation has agreed to contribute £159M towards construction and operation of the memorial but still needs to raise another £90M. The Lower Manhattan Development Corporation has committed £132M.
The memorial is expected to open on 11 September 2009.