The tribalism that grew up on the pile had origins so primitive that they can only be understood as instinctual. At the core was an us-versus-them mentality brought on by the mere act of donning a uniform. Whether as firefighters or as the two sorts of police (city and Port Authority), the uniformed personnel at the site were generally drawn from the same white "ethnic" outer-borough neighborhoods and families, but as members of their respective organizations they had learned to distrust and resent the others. The hostility was historical, and because it was strongest on the lowest levels, among the rank and file, it had proved impossible to root out. People at the site referred to it alliteratively as the Battle of the Badges. Across the years it had led to frequent arguments over turf and occasional bouts of outright obstructionism at emergency scenes. At the Trade Center it had been a factor from the first moments after the attack, when the Police and Fire Departments had set up separate command posts several blocks apart, and without communication between them. There were consequences to this: after the South Tower fell, police helicopter pilots took a close-up look at the fire in the North Tower, and twenty-one minutes before the final collapse they urged their own command to evacuate the building. The warning was radioed to the policemen inside the North Tower, most of whom escaped, but it was not relayed to the fire commands, or to the firemen in the building, only some of whom were able to hear independently radioed orders to evacuate, and more than 120 of whom subsequently died. The lack of communication was certainly no more the fault of one side than of the other, but it aggravated the divisions between them. Even during the initial desperate search for survivors the police and firemen quarreled over turf, and asserted their differences. By the end of the first day the bucket brigades had separated according to uniform. Throughout the months that followed, individual friendships and family ties cut across the lines. Nonetheless, the tribalism festered and soon infected the construction crews, too, who did not quarrel much among themselves but generally distrusted the police as ordinary citizens do, and who probably hadn't given firemen much thought before but came now to resent their claims to special privilege on the pile.
And so the recovery proceeded, not as a united or a heroic exercise but as a set of accommodations worked out among self-centered groups sharing a pragmatic understanding that this was an important job, and that it was primarily a physical one. The only solution was to attack the ruins—to cut and drop the skeletal walls, lift the heavy steel, chew up the rubble mountains, pause to recover the dead, demolish the stump of the Marriott hotel, tear down the burned-through hulks of Buildings Four, Five, and Six, stabilize the neighboring high-rises, shore up the damaged subway, excavate the insanely packed foundation hole, reinforce and protect the slurry wall, and run a fleet of trucks and barges to haul the debris away. About halfway through Ken Holden said to me, "Excavation, remains, recovery, removal—repeat," because in essence that cycle constituted the work. But of course the complications were considerable.
The stars of the show were the machines themselves, and particularly the big diesel excavators, marvels of hydraulics and steel, which roamed through the smoke and debris on caterpillar tracks and in the hands of their operators became living things, the insatiable king dinosaurs in a world of ruin. They came in various sizes, from the "small" 320s (which could pull apart an ordinary house in minutes) to the oversized 1200s, monstrous mining machines rarely seen in New York, which proved to be too awkward for many uses on the pile. Most of the work was done by the 750s—sufficiently big, sufficiently lean, enormously persistent beasts that battled the debris without rest. Each 750 weighed in at 180,000 pounds (as compared with 140,000 pounds for the heaviest trucks fully loaded), and was equipped with an articulating arm and one of three hydraulically powered attachments—steel-cutting "shears" (often attached to an extra-long arm, for reaching high or wreaking havoc deep inside the standing ruins); conventional "buckets," useful at the lower levels of the pile in areas of pulverized debris; or, most often, "grapplers," gap-toothed claws that could open eight feet wide, but could also close into an overbite so tight that it could snap twigs. The grappler-equipped excavators (known simply as grapplers themselves) dominated the battle until it moved well below ground. Working fast and in tandem, the machines picked the ruins apart one piece at a time. The steel they took on included the heaviest ever used in a building—box columns weighing 3,100 pounds per foot, so that a merely man-size length would amount to almost 19,000 pounds, and a fifty-foot section would come in at nearly the weight of the grappler itself. Some of the loose steel could be "flown" out by the enormous cranes that ringed the pile—but the process was so tedious that it was reserved for special cases: for instance, for lifting beams during the search for survivors among ruins too rough to allow the grapplers access, or for the dismantling of the skeletal walls, most of which were torched apart one section at a time by ironworkers in suspended baskets, and then lowered gently to the ground. This left the bulk of the fight to the grapplers, which were just tough enough to take it on.