A Centuries-Old Underworld Of Caverns, Squatters And Unmarked Doors

Early in 2011, Leader happened across some SLOSH-based maps for the first time. SLOSH is a contrived acronym standing for Sea Lake and Overland Surges from Hurricanes. It is a National Weather Service computer model that excludes the effects of rainfall and predicts flooding purely on the basis of astronomical tides and the mounding of water caused by the various categories of hurricanes. The margin of error is large, about 20 percent, but what the maps clearly show is that low-lying parts of New York, including much of the tip of Manhattan, are at risk of complete inundation if a surge from even the merest Category 1 hurricane happens to coincide with an astronomical high tide. This may seem intuitively obvious, since normal high tides rise so close to the city that the harbor regularly looks like a bathtub about to brim over, but the SLOSH maps are authoritative, and because they integrate surface elevations into predictive graphics, they add important practical details street by street. Leader remembers being impressed by them, but busy. Like those around him, he shelved the maps and carried on with his daily urgencies.

Then, suddenly, in late August 2011, Hurricane Irene came barreling straight at New York. It was a Category 3 crossing the Bahamas and was expected to weaken to a Category 1 before its arrival, but pushing a surge ahead of it. Unwilling to gamble on the timing of tides, the subway leadership hastily discarded the existing plans for surgical rainfall defenses and grabbed the SLOSH maps to improvise a wholesale effort to waterproof the underground against entire districts overhead that might soon lie beneath the harbor’s waters. Work crews boarded over more than 700 sidewalk grates. On the afternoon of Saturday, August 27, passenger service was suspended pre-emptively for the first time in the subway’s history, and the trains were driven to the safety of high ground. By then it was known that the storm would hit on a Monday, and, as luck would have it, indeed at high tide. The surge was forecast to be 11 feetâ€"not an 11-foot wall of water, as people may imagine, but a quiet upwelling of water five feet higher than the normal six-foot tide. The rising water would top the banks at 10 feet and cover areas of Lower Manhattan to a depth of one footâ€"an unimpressive number in itself but backed by the entire Atlantic Ocean relentlessly seeking ways into New York’s underground. Any gaps left in the defenses would lead large parts of the subway to flood, including some of the critical under-river tunnels. In one of those tunnels, on the 14th Street L line, crews stripped out the entire computer-based signaling systemâ€"a one-of-a-kind asset that could not soon be replaced if things went wrong. Elsewhere, workers erected plywood-and-sandbag dams about four feet high across the lowest station entrances. Then people sat back to wait in suspense.

But Irene turned out to be a dud. By the time it arrived over New York City it had weakened into a tropical storm with insufficient rain even to fill the drains. On the morning of Sunday, August 28, Leader accompanied Transit’s president, a friend named Thomas Prendergast, on a mission to Battery Park to watch the surge come in. At around 10 A.M., when the water reached its maximum height, it was lapping up some harbor-front stairs at their feet but couldn’t even make it to the streets. The subway remained dry. New Yorkers got back to griping about the service, and the underground returned to normal.

One year later, in October 2012, Hurricane Sandy should have been much the same. It was an extraordinarily large hurricane, and formerly a Category 3, but it was weakening, and, as with Irene, it was expected to become something less than a hurricane before it arrived. If it hit New York at high tide, the surge was again predicted to be 11 feet. To Leader, Prendergast, and others at headquarters, this now seemed like familiar territory. They knew that their defenses had not actually been tested by Irene, but they were lulled nonetheless by their satisfaction that the subway had emerged unscathed. In preparation now for Sandy, they decided to do what they had done before. By Sunday night, on the eve of the hurricane, the work was completed, and an eerie calm prevailed. Leader sat with Prendergast and a few others in a designated Situation Roomâ€"a windowless enclosure equipped with phones, televisions, and laptop computersâ€"above the subway’s Rail Control Center, in Midtown Manhattan. They had placed roving patrols into the tunnels to monitor conditions, but no calls were coming in. Their only sense of the weather outside came from reports on TV.

It was the same for much of the following day. The storm was running behind schedule and was now expected after dark, pushing a surge that would correspond with high tide. That was all right, they thought; they were prepared for the coincidence.

After dark Prendergast gathered Leader and another top hand, Carmen Bianco, for a trip downtown to Battery Park. This was the ride with the National Guard. The truck was a diesel beast, a bellowing high-clearance deuce-and-a-half. Prendergast and Bianco sat in the back on benches; Leader sat crammed between two soldiers on a jump seat in the cab, giving directions. The streets were deserted, and glistening from a gentle rain. They tried to descend 11th Avenue near the Hudson, but found that it was already flooding; shifting east to higher ground, they continued down 9th Avenue, past 14th Street and into the Meatpacking District, where suddenly they found themselves in deep water. Leader thought, Water in the Meatpacking? What the hell’s going on? He guessed it might be rainwater caused by a clogged drain. But then from the back of the truck Prendergast called him on his cell phone and said, “There’s a report from a buoy in the harborâ€"we’re looking at a surge of 14 feet!” Leader said, “Holy shit!”

He does not want his mother to hear him using such language, but he knows that she knows that he does. Blocks before the truck reached Battery Park, it was stopped by ocean waters. Prendergast and Bianco climbed out, each on his own way to survey the scene. Leader got the truckdriver to ferry him through water three feet deep, to the four-foot-high plywood barricade across the north entrance to the new South Ferry station. This is when he became the first person in New York to understand that it was not just the surface but the underground that was flooding. He found Prendergast, gave him the bad news, and went down into another subway line and saw flooding of equal concern. Back on the surface the cell phones were going crazy. Water was pouring in at multiple points in the system, fires were burning from electrical shorts, and the pumps were being submerged and destroyed. Meanwhile, Consolidated Edison, the electric company, was trying to save its own equipment by de-energizing the circuits, but it could not move fast enough to prevent an explosion at an East River substation that blacked out all of Manhattan below 39th Street. Prendergast collected his crew and roared back to the Rail Control Center, where bedlam had broken out. Leader ordered all power to be shut off throughout the rails and stations in Manhattan and in some places beyond, and asked for the first systematic assessments of what had gone wrong.

Much was known by dawn. There was extensive damage to the signals, wires, pumps, communication equipment, and relays. Of the many underground stations affected, five suffered major damage, including the new South Ferry station, which, as it turned out, was destroyed by freakish circumstance: a heavy bundle of two-by-six lumber floating in the surge rammed through the plywood defenses at the main entrance in front of the Staten Island Ferry terminal, allowing the harbor to cascade down the stairs and escalators into the fare area, rush through the turnstiles, and, turning left, continue down another level into the station, which it filled to a depth of 80 feet, flooding a signal relay room, a circuit-breaker house, elevators, escalators, electrical distribution rooms, a pump plant, a ventilation plant, an air-tempering plant, communications rooms, and a train dispatchers’ office loaded with electronic equipment. Making matters worse in the same location, a passageway to the right allowed the harbor simultaneously to cascade down another flight of stairs into a connecting station called Whitehall, from which the water flowed downslope into the twin 20.5-foot-diameter tubes of the Montague, an under-river tunnel on the R line to Brooklyn, which was soon filled to the brim. To varying degrees, other under-river tunnels flooded as wellâ€"8 of the subway’s 14â€"because as low points they served as drains for the water that was pouring into the system all along the East River shorelines. That water came through unprotected station entrances and ventilation grates, through manhole covers (which turn out not to be watertight at all), and through the trapdoors of the subway’s emergency exits, each of which, it was later calculated, leaked at the rate of a million gallons an hour.