When Science Goes Wrong (18 page)
Mulholland and his chief assistant, Harvey Van Norman, immediately drove from his downtown office to the dam site, which they reached around 10.30am. They confirmed that muddy water was indeed flowing down the foundations of the right abutment, at a rate of about 15 gallons per second. When they clambered up to the site where the water was emerging from the Sespe Formation, however, they saw that the water was clear. The mud was mixing in as the water ran down the slope and across the embankment of a dirt road. Some water was also leaking from the base of the other, left, abutment, but this water was also clear. Relieved to find that the dam was not being undermined, Mulholland made a mental note to have the leaks repaired at some later date, and he and Van Norman returned to the city.
The dam broke at two-and-a-half minutes before midnight that evening. There were no surviving eyewitnesses to the collapse, but the exact time could be pinned down because it caused an interruption in the transmission of electric power in lines that ran down the canyon. The interruption was experienced in Los Angeles only as a two-second dimming of lights, but areas closer to the dam were plunged into darkness.
It is likely that Harnischfeger and Johnson did witness the dam’s collapse before they became its first two victims. Leona Johnson’s fully clothed body was later found trapped amongst the slabs of broken concrete at the base of the dam. Most probably Harnischfeger and Johnson saw or heard some premonitory sign of the collapse, dressed and walked up to the dam to see what was wrong, only to be caught by a cascading mass of water and concrete. Harnischfeger’s body was never found, nor was that of his young son.
A few survivors did hear or feel the collapse. A motorcyclist named Ace Hopewell was driving up the valley shortly before midnight. The road ran along the canyon’s east wall: at the point that it passed the dam, it was cut into the Pelona Schist only 13 feet above the dam’s left abutment. Hopewell noticed nothing amiss as he passed the dam, but a mile farther up the road he heard a sound as of rocks falling. He stopped for fear of running into a landslide, but the sound seemed to be coming from behind him so he continued on his way.
EH Thomas was one of the staff of the lower powerhouse, which was situated in the canyon a mile and a half below the dam. His particular job, however, was to attend to the surge tank, high on the east rim of the canyon. The surge tank’s function was to damp out violent changes in hydrostatic pressure caused by the opening and closing of valves; from the surge tank, pipes (or ‘penstocks’) carried the aqueduct water down to the twin generators in the main powerhouse building. Thomas lived with his mother in a cottage not far from the surge tank. At about midnight the two were woken by a strong shock, followed by a continuous vibration. They first assumed that it was an earthquake. Thomas dressed, took a flashlight, and made his way toward the tops of the penstocks. Looking down into the canyon, he saw nothing but rushing water. The powerhouse, if it still existed, was completely overtopped by the flood, which scoured the canyon walls to a height of 120 feet above the creek. Thomas realised that the 28 other powerhouse workers and their families, whose homes were in the floor of the canyon, had most likely been swept away to their deaths.
Actually, three people did survive. One was Ray Rising. ‘I heard a roaring like a cyclone,’ he said later. ‘The water was so high, we couldn’t get out the front door… in the darkness I became tangled in an oak tree, fought clear, and swam to the surface… I grabbed the roof of another house, jumping off when it floated to the hillside… There was no moon and it was overcast with an eerie fog – very cold.’ Rising met up with a worker’s wife, Lillian Curtis, and her young son, who had had similar narrow escapes, and the three of them waited for the dawn together, but his own wife and three daughters died, along with 64 other members of the powerhouse community. The powerhouse itself, a 65ft-high concrete building, was swept away – only the generators remained in place, half-buried in mud.
The floodwaters rushed onward. About 15 minutes after the dam broke, the flood reached a cattle ranch near the southern end of the canyon. All the buildings were swept away, along with several of the residents, but a few had been woken by the noise and were able to scramble to higher ground.
At the southern end of San Francisquito Canyon, the creek joins with those from several other canyons to form the Santa Clara River, which runs 40 miles westward to the Pacific Ocean south of Ventura. Near where the creeks meet lay the small community of Castaic Junction – basically an auto park, with tourist cabins, a gas station, a cafe, and a few other buildings, which served travellers on the highway that connected Los Angeles with California’s Central Valley.
It took 50 minutes for the floodwaters to reach Castaic Junction, but they had lost little of their ferocity along the way. George McIntyre, the 19-year-old son of the auto park’s owner, was alerted by the rushing, crashing noises coming from the east. He, his father, and their cook went outside to see what was happening. They saw bright flashes from the direction of the Edison station at Saugus, and they concluded that there was something amiss there. Then they watched with amazement as one of the tourist cabins began moving off its foundations. Within moments the father and son were knocked off their feet by the floodwaters. While holding on to each other, the two men were swept away, but not before they caught a final glimpse of George’s younger brother struggling to get through the window of one of the cabins. After a while George and his father, were able to grasp onto a utility pole, but the father was injured, probably by floating debris, and after muttering a brief good-bye to his son he let go his grip. That was the last George saw of him. Eventually, George also let go of the pole and was sucked deep into muddy water. At long last, he found himself back at the surface, half-choked with water and mud. After drifting for some time he collided with the branches of a cottonwood tree, where he was able to hold on until the flood had receded. Besides George McIntyre, only one other person survived from the Castaic Junction community – the cook, who escaped the floodwaters by running to higher ground. All the structures were completely destroyed, and four miles of the north-south highway were inundated.
By this time, the wider world was beginning to find out about the catastrophe. The initial break on the Edison line had been followed by a cascade of wider electrical failures, as more lines were brought down, switching stations were shorted out and emergency connections were overloaded. Soon the city of Los Angeles, the Antelope Valley and all the coastal cities north to Santa Barbara had lost power. Charles Heath, Edison’s superintendent of transmission, later testified that he had guessed as early as 12.05am that the St. Francis Dam had failed, and that, after telling his subordinates to warn the towns in the Santa Clara Valley, he set out for Saugus in his official car, with siren blaring and red light flashing. He said that he reached Saugus at about 12.45am – just about the same time that the floodwaters were entering the head of the valley.
Heath knew that 150 Edison workers were sleeping in tents at a construction camp on the bank of the Santa Clara River, eight miles down the valley. He couldn’t reach them, because the road and the bridges were out, so he attempted to telephone the camp from the Saugus substation, which itself was being inundated by the rising water. No one answered the phone and then, after several repeated attempts, the line went dead. The flood, forming a wall of water 40 feet high or so, had struck the camp without any warning. Of the 150 workers sleeping there, 85 died. Few of them had even been able to get out of their tents.
Further down the valley were the towns of Fillmore and Santa Paula. The destruction of roads, bridges, power lines, and telephone lines had cut them off from any communication to the east, but at 1.30am the night telephone operator at Santa Paula received a call from the coast: the St. Francis Dam, she was told, had broken and floodwaters were descending the Santa Clara Valley. Working by candlelight, the operator began calling local police officers, town officials and the residents of the town whose homes were closest to the riverbed. Two police officers drove through the streets on their motorcycles with sirens blaring. They stopped at every third house or so, warning the sleepy occupants of the oncoming flood and telling them to alert their neighbours and move to higher ground. Soon the entire town was on the move. Meanwhile, squad cars raced up the valley to Fillmore and alerted the population there. As the cars attempted to drive farther east, however, they were stopped by the arriving flood, which filled the entire two-mile width of the valley and was advancing westward at about 12 mph.
Much of the Santa Clara Valley was used for citrus farming and other tree crops. The groves were obliterated by the oncoming water and mud. In addition, the low-lying portions of the valley towns, especially Santa Paula, were inundated. Houses were carried off, to be smashed up by the roiling water or to be left reasonably intact but several blocks away from their foundations. The bridges across the river were destroyed: the bridge at Santa Paula was demolished just minutes after a police officer ordered a crowd of would-be spectators to get off it.
As the floodwaters moved westward, they also slowed and spread out. By the time they reached the coast, five hours after the dam broke, they were moving at no more than a jogging pace. The coastal city of Oxnard was evacuated, but that turned out to be unnecessary.
The total death toll was estimated to be between 400 and 450 persons. This figure may be an underestimate, given that then, as now, many undocumented migrants from south of the border lived in the low-lying areas of the canyons and riverbeds. Though impromptu morgues overflowed with bodies, many of the dead were never found. Some were undoubtedly swept out to sea: bodies washed up on beaches as far south as San Diego. Others were buried under many feet of mud. In addition to the human toll, there was enormous destruction of livestock, buildings, infrastructure, orchards, and farmland.
Eventually, the city of Los Angeles settled with most of the victims of the disaster without litigation. Persons who had lost family members typically received $10,000 to $20,000 – or $100,000 to $200,000 in today’s dollars. In one case that did go to court, Ray Rising, the sole worker to survive at the lower powerhouse, was awarded $30,000 for the loss of his wife and three daughters.
What caused the dam to fail? William Mulholland himself, accompanied as always by Harvey Van Norman, rushed to the dam site in the small hours of the morning after the disaster. As dawn broke, an extraordinary scene revealed itself. A slim central section of the dam still stood in its original place, ranging 200 feet above the empty reservoir like a lone incisor in an otherwise toothless jaw. To its left, another huge section of the dam had slumped downward and across the surviving upright section, shearing off much of its stepped downstream face. This section had broken into three or four giant blocks. But the remainder of the dam, including its left and right abutments, were simply gone – carried as much as a mile down the canyon by the floodwaters. The rocky foundations of the abutments had also been scoured away to a depth of 20ft or more. The left wall of the canyon had fallen away in a giant landslide, carrying a stretch of the roadway with it. Evidently the material in this slide had mixed in with the floodwaters, turning them into a slurry that was dense enough to freight the huge blocks of concrete far down the canyon.
Surveying the scene, Mulholland immediately suspected sabotage. After all, the aqueduct itself had been the object of dynamite attacks just a few months earlier, so why not the dam, too? Mulholland mentioned or hinted at sabotage as the cause on several occasions, such as at the coroner’s inquest on the victims of the disaster. Some experts presented what purported to be evidence of sabotage, such as the presence of dead fish that were supposedly stunned by an explosion.
Still, the sabotage theory never really took hold, and with good reason. It would have been an enormous undertaking to bring down the dam, far beyond what could have been accomplished unnoticed by a small team of saboteurs. Furthermore, the seismological station at Caltech would have recorded the tremors induced by the blast, but inspection of the records showed nothing unusual at the time of the failure. To his credit, Mulholland did not use the sabotage theory to weasel out of responsibility for what had happened. He told the investigators, ‘If there is an error of human judgment, I am the human,’ and he was so laden by guilt that he professed an envy for those who had died.
There were, of course, investigations into the cause of the dam’s failure. The most high-level of these was a commission of inquiry set up by the governor of California. The commissioners consisted of six engineers and geologists, including professors from Caltech and the University of California, Berkeley. Perhaps responding to the pressure of a public outcry, the commissioners carried out their task with extraordinary speed. They met for the first time on March 19, made a single visit to the dam site, and issued their final report on March 24, just 12 days after the disaster.
During their visit to the dam site, the commissioners noted the unusual characteristics of the Sespe conglomerate near the San Francisquito Fault. ‘When entirely dry it is hard and rock-like in appearance,’ they wrote, but in reality it was ‘held together merely by films of clay,’ and when placed in water it ‘quickly softened and turned into a mushy or granular mass.’ The commissioners also had compression tests done, which revealed that, even when dry, the rock of the Sespe conglomerate in the dam’s right foundation was far weaker than the concrete of the dam itself.
