There is good news for residents on 72nd Street on the Upper East Side, as the Metropolitan Transportation Authority on Monday announced it has finished blasting rock as part of the Second Avenue Subway project.

Since January 2011, the agency has been working to create an underground cavern for the new 72nd Street subway station.

The final blast occurred Thursday.

The work has raised questions about air quality in the city.

The contractor is now working to waterproof and reinforce the underground cavern.

The $4.45 billion project is the largest expansion of the subway system in generations.

The expansion from 72nd to 96th Streets is expected to open to the public in December 2016.