A major rail project below New York’s Grand Central Terminal is underway, including tunnelling works costing $1M (£650k) per foot (0.3m).
The East Side Access project includes a new terminal 14 storeys deep below Grand Central, as well as delivery of a 120ft-long (36.6m-long) tunnel which will provide a faster commute from Long Island and Queens to the east side of Manhattan.
The revised budget for the project is $10.2bn (£6.6bn), which is more than double the original cost.
Speaking to the Associated Press, a Metropolitan Transportation Authority (MTA) spokesman said some of the cost overruns are due to the need to keep trains running while work is being undertaken.
The scheduled completion date is 2022, more than a decade later than initially anticipated.
MTA officials have said the delays have been caused by the challenge of securing funding while removing millions of cubic yards of material from blasting and boring through rock and mud at the site.