A mega construction project slowed by delays is inching along way underground.
NY1 transit reporter Jose Martinez takes us deep beneath the city's streets for a look at East Side Access.

They're digging deep below Grand Central.

In caverns more than 120 feet beneath Park Avenue, sandhogs remain hard at work creating a train station that, by August 2019, should welcome Long Island Rail Road commuters into Manhattan's East Side.

That's three years behind schedule, but a milestone is expected by the end of the month, when blasting to create the caverns wraps up.

"This job is the biggest one I've ever been on, and I think it's the biggest one anyone is ever going to be on," said senior field manager Bill Ury. "I can't imagine much more."

Hampered by cost overruns and years of delays, the $8.2 billion East Side Access project will welcome LIRR trains into Grand Central for the first time through eight tunnels and four platforms carved out of Manhattan bedrock.

Four more tubes are being carved in Queens. They'll connect commuter trains to a tunnel that already runs under the East River. That, in turn, will carry the trains to the new tunnels, delivering an estimated 160,000 riders into Grand Central every day.

"Customers will save up to 40 minutes a day in commuting time," said MTA spokesperson Aaron Donovan. "Rather than going all the way to Penn Station and backtracking via the subway or on foot, they'll be able to come right here to the East Side."

A former rail yard beneath the station will be transformed into 22,000 feet of retail space.

East Side Access is a huge part of the first expansion of the LIRR in more than a century.

Even 14 stories below street level, the work never stops. But when it eventually does, transit officials insist that the project will be worth it to commuters.