Crews sweep debris off of Second Avenue in the aftermath of yesterday’s explosion. (Photo via Noray Joseph)

In the aftermath of yesterday’s explosion in the 72nd St. station cavern, the MTA has suspended work at the site pending an investigation. Neighbors and politicians, long wary of the disruptive project, are clamoring for answers, and MTA head Joe Lhota hopes to give them some. He said in a statement released late last night:

“What happened at the Second Avenue Subway construction site today is completely unacceptable. The MTA is investigating what went wrong and will not resume work at the 72nd Street site until we receive a full explanation for what happened and a plan to make sure it does not happen again. While I am thankful that no one was injured today, I fully understand why neighbors of the construction site are upset. I am, too. The safety of the community is the MTA’s utmost priority. We will continue working with the community to ensure their concerns are heard and acted upon.”

Meanwhile, as information begins to trickle out, there are some causes for concern. Despite the overall safety of this project — it’s orders of magnitude safer than it was 100 years ago — the contractors may not be doing enough to fully ensure the protection of these active work zones. One source said to amNew York’s Marc Beja that the deck on the street was “not able to withstand the force of the blast because it was not anchored in.” I’m sure we’ll hear more stories like this in the coming weeks.

Updated (3:25 p.m.): According to eyewitness reports and alerts from the city’s emergency management office, Fire Department and EMS workers are on the scene at 72nd St. at 2nd Avenue where a explosion in the Second Ave. Subway station cavern at that site went awry. Bystanders say a blast sent rocky debris flying and may have damaged sidewalks. There were somehow no reported injuries, but East 72n St. is now closed from 1st to 3rd Avenues. The Times had the following report while The Daily News had some very dramatic photos:

An intentional underground explosion on the Second Avenue subway project at 72nd Street broke windows above ground Tuesday afternoon, the authorities said. There were no reported injuries. “We were doing a controlled blast,” said Adam Lisberg, a spokesman for the Metropolitan Transportation Authority, “when clearly something went awry and an explosion was felt at street level.” The blast occurred around 12:45 p.m.

Michael Horodniceanu, president of the M.T.A.’s capital construction division, said that workers had been blasting to clear an escalator wellway from the street to the subway, but that “we do not know why” the blast caused damage up on street level.

Windows were cracked on several floors of the building at the southwest corner of Second and 72nd that houses the Kolb art gallery, including in the gallery itself. Inside it, people could be seen inside cleaning up what looked like debris.

Reporting from the scene, amNew York’s Marc Beja had a bit more:

RT @marc_beja: Explosion caused no utility damage, minimal structural damage. Mostly busted windows. Blast was to make elevator shaft

— Second Ave. Sagas (@SecondAveSagas) August 21, 2012

Apparently, this is not the first time a blast at 72nd St. did not go as planned as the MTA says something similar happened earlier this summer. The MTA, meanwhile, has said construction at 72nd St. has been halted while an investigation into the cause of the accident is underway. Despite some grandstanding by prominent political commentators, this is one of the few serious disruptions to impact a rather complicated problem, and officials seem to be taking it quite seriously.

I’ll try to update as more news comes in. If anyone has any images from the scene, drop me a note.

A few days ago, I found myself in the 63rd St. station at Lexington Ave. I don’t often end up there and hadn’t swung by to check in on the Second Ave. Subway construction in a while. With trains rumbling through a station stripped bare of its finishes, it’s quite a sight to see. Gone are the red faux-walls that hid the two-track platforms. Gone are the dropped ceilings that hid the arch of the tube. It is a subway station in progress.

I’d imagine a lot of riders are mystified as to what’s going on there. It was never immediately evident that the northern side of that station hid another set of functional tracks, but with the arrival of Phase 1 of the Second Ave. Subway, that station will have a radically different look. Q and F trains will stop across the platform from each other, and the platform levels at least will have a new look. The deep bore, as well, gives us a sense of the depths of the other SAS stations as well.

If subway work is your thing, stop by that station. With the bored walls out for all to see and gaps in the blue fence providing glimpses into the unused platforms, it’s the closest straphangers can get to a station in progress.

As construction proceeds underneath Second Avenue, we tend to think of progress on a grand scale. We celebrate when the tunnel boring machine reaches its end. We bemoan air quality and noise. We await muck houses and dump trucks. We often overlook the people who are underground everyday building this subway.

This week, The Village Voice takes a journey into the Second Ave. Subway, but it’s not your typical journey. While we may marvel at scope and size of the project, the Voice is more interested in the human side of what’s happening. This week, Sean Manning >profiles the Sandhogs, the members of Local 147 who are digging the tunnels that will one day play host to the Second Ave. Subway.

Manning’s piece traces the lives and times of these workers. Many are former military men looking to make a living back home. Take a gander at this excerpt and sneak a peek at the video above. There’s a photo slideshow as well:

That’s another parallel between soldier and sandhog life, one that particularly appeals to Buzzell: the hierarchy. Just as in the military, the sandhogs follow a strict chain of command. At the bottom is the gang, typically composed of six men. Each gang is led by a foreman, who reports to a walking boss, who in turn reports to a superintendent. Unlike the military, though, sandhog rank can change from project to project. Depending on recent performance as well as on what men and positions are available, a walking boss on one job might be a gang member on another and vice versa. Also, there is no pay grade: Except for the project superintendent, all sandhogs take home the same $45 an hour. Counting the money directed into union-benefit funds, the rate is closer to $100 an hour. In a busy year, a sandhog can make more than $100,000. (Financial compensation is one thing the sandhogs and the military most assuredly do not have in common. In 2012, basic pay for an Army private first class with less than two years of experience is $21,089.)

While the sandhogs are among the highest-earning laborers in the country, they give the lie to any public perception of union sloth, of work being needlessly, greedily dragged out. “The faster we get the job done,” says 51-year-old, 30-year-veteran Scott Chesman, “the more work the city is likely to give us.” Plus, on a job like pouring concrete, speed is imperative.

For the Second Avenue tunnels, the concrete was trucked in from Queens and delivered underground through a six-inch diameter pipe called a slick line. The slick line is screwed together in 10-foot segments, each costing $400. On this project, the slick line stretched as long as 1,500 feet. If the concrete is not applied to the tunnel quickly enough, or if the balance of retarder and accelerator in the mix isn’t precise, or if one of the trucks gets stuck in traffic, the concrete in the slick line begins to set up. When this happens, with $60,000 worth of slick line at stake, the trucks have to stop pumping, and the slick line has to be flushed, what’s called “shooting the rabbit.” That’s as much as a quarter-mile of concrete expelled into a pile that must be shoveled into muck bags—roughly 40 pounds per bag once hardened—and then wheelbarrowed and heaved by hand, bag by bag, into a dumpster. Lunch and urination are infrequent. (Even when working fast, the work is slow-going. Because of the six hours it takes the concrete to fully set and the time necessary to break down and move and reassemble the multi-ton steel arch form, progress is limited to at most 120 feet per day.)

It’s easy to lose site of the individuality of the construction work. The unions are often nameless and faceless entities that insist on work rules too onerous for our times. They are a politically powerful force but are also one of the reasons why construction work in New York City is so expensive. The city relies upon them for progress but may also be hindered by their demands as well.

The tragic accident last week at the site of the 7 line extension served as a reminder of the human element involved in that project and other tunnel work. Back in the early 20th Century, many New Yorkers lost their lives digging out the first subway, and our society today does not take the time to remember those workers. Today, safety is paramount, and accidents are few and far between. Yet, people are in there everyday, wading through dank tunnels working to extend our transit system. This is but a small snapshot of who they are and what they’re doing.

The Wall Street Journal and The Daily produced the above video on the Second Ave. Subway, and although it’s mostly just an overview of the project, the scenes are, as always, awe-inspiring. The reporters call it the most complex construction project in New York City, and that’s not far from the truth.

Meanwhile, the other Ben with a Second Ave. Subway-related site took a walk through the Contract One tubes recently and came back with some dramatic still photos from the construction site. It’s quite something to see how the work has progress since the TBM launched in May of 2010 and since my last visit in March of 2011. Just four years and 8.5 months of construction left, if all goes according to schedule.