He pointed to a man then pointed to a building, each assigned the number in the pamphlet. "You, four. You, five. You, six. You, seven. D.J. and I will take the two towers closest to the hotel. If you see anything, let us know. We'll reassign manpower as needed."
The soldiers dispersed, moving in pairs. Even-numbered buildings were on the left; odd numbers were on the right. The men would travel together until they were forced to split up.
Payne and Jones were the last to leave. They lingered in (he subbasement for an extra minute, looking for something to improve their odds, hoping to find a better map, one with floor plans or mechanical drawings. Anything to point out the weaknesses that Schmidt might have spotted when he did his research.
As it turned out, their biggest break wasn't an object. It was a sound. A simple sound. Nothing more than a drip of liquid falling on concrete. Like a droplet of rain hitting the sidewalk. Jones heard it as he searched for paperwork. On most occasions it would have blended into the outside world and he would have ignored it. But in this case, his senses were in overdrive. Adrenaline was flowing, and everything around him was part of a much bigger puzzle.
A sound could be a footstep. A sound could mean his death.
Drip. Somewhere to his left.
Drip. Back near the maintenance shaft.
Drip. What was that smell?
Suddenly his curiosity was doubled. Not only was there a noise, but there was an odor. A familiar scent that reminded him of his time in the military. Back when he was flying planes and helicopters. Killing time in hangars. Waiting for his next mission to begin.
He took a few steps forward, searching the ceiling and floor for moisture. Finally he saw it. A small puddle underneath the massive water pipe they had followed from the hatch. Curious, he crouched and inspected the liquid. It was clear like water but had a strong chemical smell. He put his nose closer and took a whiff.
"Jon," he called over his shoulder. "Come over here."
Payne spotted him in a catcher's stance, examining a puddle on the ground. He couldn't imagine what his friend was doing. "Please tell me you didn't take a piss."
Jones ignored him. "I think it's fuel."
"What do you mean?"
"I think this pipe is leaking fuel."
"But that's a water pipe."
He nodded. "I know it is. But I'm telling you, this isn't water."
Dubious, Payne leaned closer and breathed in the fumes. An acrid stench filled his nostrils, burning the back of his throat and making him gag.
"Told you it isn't water."
Payne coughed a few times, trying to catch his breath. "What the hell is that?"
But Jones didn't answer. Instead, he took a few steps down the maintenance shaft, trying to figure out what was going on. He glanced back into the subbasement, following the plumbing, then back into the shaft again, the pieces still not fitting together. "Where do those pipes go?"
"To some private facility in the desert. Shari said the towers were so big they had to pump in their own water."
"But that's not water."
"I know it's not water. I'm still choking." He paused for a second as all the nasty possibilities started to sink in. "Wait. What do you think it is?"
"Aviation fuel."
45
When designing a skyscraper, water pressure is a significant problem that must be overcome. Large pumps in the basement usually service the lower floors. However, it is impractical to pump water directly to a penthouse, several hundred feet in the air. Most buildings are equipped with mechanical floors, every ten floors or so, which are filled with everything from air-conditioning units to ventilation systems. This is where intermediate pumps are stored, used to push water from one stage to the next until the liquid reaches its highest destination.
Unfortunately, this is an inefficient system in the tallest of buildings, always relying on the pump below to send water to the pump above. One mechanical failure and the water stops. This is a huge concern in emergency situations, when sprinkler systems cannot afford to fail because ground-based fire equipment is incapable of shooting water above certain heights.
To remedy this situation, tanks are often installed on the upper floors, where water is stored in case it is needed.
Sometimes the tanks are small, placed on every mechanical lloor in the building. Sometimes they're large, scattered throughout different parts of the system, based on estimated demand. And occasionally, in really big projects such as the Abraj Al Bait Towers, the designers opted for something different.
In the mechanical penthouse, on top of every tower in the seven-building complex, sat a water tank with a capacity of 40,000 gallons. Engineers designed these tanks with a dual purpose in mind. First and foremost, they could supply water to the 65,000 guests who would fill the towers and all the extra people who used the mall, convention center, and prayer halls. Second, the tanks served as tuned mass dampers, absorbing vibrations from high winds and possible earthquakes-not to mention 2.4 million people as they strolled through the Meccan desert during the hajj season-which helped to protect the structural integrity of the building's core.
Ironically, the tanks were installed to keep the towers standing, but they were the very things that might bring them down.
Trevor Schmidt smiled as he placed the charge along the base of the water tank.
It was the perfect choice for the perfect mission.
C-4, an abbreviation for Composition 4, was a military-grade plastic explosive, one that was preferred by the U.S. Special Forces because its velocity of detonation was ideal for metalwork. Not only was it malleable, allowing it to be molded into specific shapes or wedged into the tiniest of spaces, but it was also highly stable. It could be shot, dropped, kicked, or thrown into a fire, but it wasn't going to explode without a detonator. For the past few hours, Schmidt had carried five pounds of it in a shoulder bag and never worried about it blowing up prematurely.
Of course, there were other reasons why he'd selected C-4 for this particular job.
Personal reasons.
Due to its precision, C-4 was frequently used by terrorists, including the bombing of the USS Cole, a guided-missile destroyer refueling in Yemen, and the destruction of the Khobar Towers, a U.S. military housing development in Saudi Arabia where nineteen servicemen were killed. Both of those were horrible tragedies that deserved to be avenged, but in Schmidt's mind, they paled in comparison to the incident at Al-Hada Hospital, where C-4 was used to detonate a fuel truck parked outside the private wing where his men were staying.
That was the attack that fueled his rage.
He thought back to that painful day as he prepared the detonator. For him, it was a simple procedure, one he had done so many times in the past that it was second nature. Like brushing his teeth or tying his shoe. There were no nerves or trepidation. His hands simply did what they were trained to do.
Much like Schmidt himself.
Payne sent the transmission as he and Jones charged up the stairs. "All teams, check in for priority update. Repeat, priority update."
His men responded in turn, waiting to receive the information.
"Jet fuel has been found in the plumbing. Repeat, inside the plumbing. Focus your search on mechanical floors. Tanks and pumps are prime targets. Sweep for explosives."
There was a three-second delay before one of his men spoke. "Are floor numbers known?"