Peter Hernon - 8.4

Lauren parked. She knew one of the engineers there, Tom Davis. He was a hydrologist with the Tennessee Valley Authority. He and his wife lived up the road from her. They’d built a log cabin with a monster deck. They all went to the same church. United Methodist. Lauren recognized his pickup. Another car was next to it.

The lights were on inside the building. Lauren went into the control house, a room with large windows that overlooked the river. No one was there. She heard someone climbing up the ladder-like stairway that descended to the lower levels, where the dam’s mechanical works were located. She’d taken several tours of the place. You could actually get inside the inner walls.

Tom Davis came up the metal steps. His face was ashen. Mouth slack.

“Tom, what’s going on?” Lauren asked.

He walked past her to a panel of gauges. Spotlights illuminated the open gates and the torrents of rushing water.

“We almost lost her,” he said, leaning on both hands against the control panel. “I swear to God. We almost lost the dam.”

Lauren stared at him. Her legs felt unsteady.

Tom Davis kept talking in the same low, almost sleepy voice. Lauren wasn’t even sure he knew she was standing there.

“I was up here when that last quake hit.” He turned toward her, and Lauren saw the bright glitter in his eyes. “I heard one of the walls cracking from the strain. An inner wall down by the waterline.”

Lauren leaned against a counter and let it hold her up. She wanted, needed, to sit down. The only chair was the raised stool at the control panel. Tom Davis was gripping it hard.

“I opened the gates to get the level down,” he said, his voice soft, almost inaudible. “We’ve got to get the pressure off the wall. I don’t know how much longer the dam can hold.”

Two men hurried up the stairway from the lower level, their boots clanking on the metal steps. They wore hard hats. One of them was talking on a cell phone. They stopped in their tracks, surprised to see Lauren.

“Lady, you’ve got to leave,” one of them said. He wore a windbreaker. His close-cropped black hair was streaked gray at the temples. A big guy in a white shirt and tie at 3:00 in the morning. Broad shoulders. He looked to be in his early fifties.

“I don’t think so,” Lauren said. He reached for her arm, his jaw set. She pulled away from him.

“They’re with the Seismic Safety Commission,” Tom said in that same strangely detached voice. “They’ve been out here looking at the dam since the first quake. They came straight over after that aftershock.”

The man in the windbreaker shot him an angry glance and told him to keep quiet.

“You have to leave,” he repeated to Lauren.

“Don’t even try to lay a hand on me,” she said.

The other man had put the cell phone in his pocket. He was younger than his partner, a little shorter. “He wants the gates closed,” he said. “He wants it done now.” He sounded as if he couldn’t believe what he’d just said.

“Do it,” barked the man in the windbreaker, turning to Tom Davis.

“Who the hell are you?” Lauren said.

“Shut the goddamn gates!” the man shouted at Davis, getting right in his face.

“You want to lose this dam?” Davis said. He was about sixty years old, a small man with glasses and thinning hair. He gripped the back of the stool as if his life depended on it. “You want to take responsibility for that, for what will happen?”

“Shut the fucking gates! That’s a direct order.”

“No,” Tom Davis said in a slow, steady voice. “I want that in writing.”

Lauren saw flashing lights outside. Two highway patrol cars had pulled into the parking lot. Men started piling out. Doors slammed.

Three troopers entered the powerhouse. They wore gray jackets with black belts over the shoulders and Smoky the Bear hats.

“Get this woman out of here!” the man in the windbreaker snapped. His voice was high-pitched and hoarse, almost a scream.

The trooper glanced at Lauren. She knew several state police officers, but not him.

“Are you the guy with the earthquake safety commission?” the trooper asked. The man in the windbreaker showed him an ID.

Turning to Lauren, the trooper said, “Ma’am, you’ve got to leave this building and get off the dam.” Even as he spoke, he was opening the door for her.

“They want Tom to close the gates,” Lauren said, trying to explain what was happening, what was at stake. She felt light-headed, breathless. Then angry at the strong-arm police tactics. “The dam has been damaged. He’s afraid it will give way unless the water’s released to ease the pressure.”

Saying nothing, the trooper led her outside and told one of his men to escort her off the dam. Immediately.

As she walked to her pickup, a trooper was in lockstep right at her elbow. He looked nervous and didn’t say a word. More police cars were driving onto the dam, blocking both ends. They were closing it to traffic.

Lauren opened the door to the pickup and slid behind the wheel. She started to say something, to try one last time to make the trooper understand what Tom was telling them. Then she paused and listened. At first she didn’t realize what she was hearing.

Silence. The roar of the water going through the gates had stopped.

IT WASN’T MUCH, A GENTLE CREST ON HIGHLAND Avenue about thirty feet high and three hundred yards long, but crucial ground in analyzing what happened during the earthquake. Culp’s Nursery was located there—a couple of glass greenhouses and a small lot for seedlings and other plants. The earthquake had shaken them so badly that the walls had disintegrated. The small store that had sold gardening tools and other supplies looked like it had imploded.

Atkins and Walter Jacobs had gone there to take a look. Sensors at the University of Memphis about two miles away showed some of the strongest vertical shaking ever recorded during an earthquake at that small hill. The results were so unexpected that they’d rechecked the instruments to see if they were properly calibrated. Slow S-wave velocities and soft soil conditions were a deadly combination. The ground had shaken like a bowl of jelly. Fortunately, no one was there when the quake hit. The only casualty was a dog, a big Rottweiler the owner kept on the premises for security. A stone planter had toppled from a shelf and split the animal’s skull.

The velocity of the secondary or S waves as measured in meters per second astounded Atkins. He’d never seen anything like it—even at the scene of far bigger quakes. The hill had experienced severe vertical shaking for nearly thirty seconds with an S-wave velocity of 150 meters per second. More typical readings were anywhere from 250 to 800 meters per second with shaking of a much shorter duration. In soft ground, the slower velocities triggered more severe shaking.

S waves, as Atkins well knew, were tricky and far more damaging than P or primary waves. Distortional, the S waves moved with a side-to-side shearing motion that could make the ground move either vertically or horizontally. P waves, by contrast, traveled faster, but moved in only one direction. Both were “body waves,” meaning they moved upward from the earthquake focus underground, the hypocenter, to the surface.

“Can you imagine what would have happened if a hotel had been up here instead of a nursery?” Jacobs said as they picked their way through the rubble.

The hill was at the southeastern end of Memphis. Atkins and Jacobs had set up three portable seismographs there to record the aftershocks, which were occurring with increasing frequency after a slow start. They’d already had a magnitude 4.1 and two in the 3.6 range. The biggest, a magnitude 5.1, had hit earlier that morning near Kentucky Lake.