“Ignorance or carelessness is shown in the reconstruction, for the middle of the new dam was nearly two feet lower in the middle than at the ends. It should have been crowned in the middle by all the rules and practice of engineering.
“Had the break begun at the ends, the cut of the water would have been gradual and little or no harm would have resulted. And had the dam been cut at once at the ends when the water began running over the center, the suddenness of the break might have been checked, the wall crumbling away at least more slowly and gradually and possibly prolonged so that little harm would have been done.
“There was an overflow through the rocks in the old dam, which provided that the water must rise seven feet above the ordinary level before it would pass over the crest of the dam. But, owing to the raising of the ends of the dam in 1881, without raising the crest, only five and a half feet of water was necessary to run water over the middle of the dam. And this spillway, narrow at best, had been further contracted by a close grating to prevent the fish from escaping from the lake, while the original discharge pipe at the foot of the dam was permanently closed when the dam was constructed. Indeed, the maximum discharge was reduced in all directions. The safety valve to that dangerous dam was almost screwed down tight.
“There seems to have been no leakage through the dam, its destruction resulting from its running over at the top. The estimates for the original dam call for half earth and rock, but there is no indication of it in the broken dam. The riprap was merely a skin on each face, with loose spawls mixed with the earth. The dam was 72 feet high, 2 inches slope to a foot inside, 1½ inches to a foot outside slope and 20 feet thick at the top. The fact that the dam was a reconstructed one, after twenty years disuse, made it especially hard on the old dam to withstand the pressure of the water.”
EVERYTHING OVER IN A FEW MINUTES.
All was over in a few moments’ time. The flood rushed down the valley when released from its prison, swept earth, trees, houses and human beings before it, depositing the vast debris in front of the railroad bridge, which formed an impassable barrier to the passage of everything except the vast agent of destruction—the flood—which overflowed it and passed on to wreak fresh vengeance below.
One of the most terrible sights was the gorge at the railroad bridge. This gorge consisted of debris of all kinds welded into an almost solid mass. Here were the charred timbers of houses and the charred and mutilated remains of human beings. The fire at this point, which lasted until June 3 and had still some of its vitality left on the 5th, was one of the incidents of the Johnstown disaster that will become historic. The story has not been and cannot be fully told. One could not look at it without a shock to his sensibilities. So tangled and unyielding was the mass that even dynamite had little effect upon it. One deplorable effect, however, was to dismember the few parts of human bodies wedged in the mass that the ruthless flood left whole.
From the western end of the railroad bridge the view was but a prelude to the views that were to follow. Looking across the gorge the first object the eye caught in the ruined town is the Melville school, standing as a guardian over the dead—a solitary sentinel left on the field after the battle. Still further on and near the center of the town were the offices and stores of the Cambria Iron Company. Beyond and around both buildings were sand flats, mud flats until the 29th of May, the almost navigable water of the flood itself until the 2d of June, the most populous and busy part of the city until the 31st of May. Part of the ground was covered by a part of the shops of the Cambria Company. Not a vestige of these remained.
When the great storm of Friday came, the dam was again a source of uneasiness, and early in the morning the people of Johnstown were warned that the dam was weakening. They had heard the same warning too often, however, to be impressed, and many jeered at their informants. Some of those that jeered were before nightfall scattered along the banks of the Conemaugh, cold in death, or met their fate in the blazing pile of wrecked houses wedged together at the big stone bridge. Only a few heeded the warning, and these made their way to the hillside, where they were safe.
Early in the day the flood caused by the heavy rains swept through the streets of Johnstown. Every little mountain stream was swollen by the rains; rivulets became creeks and creeks were turned into rivers. The Conemaugh, with a bed too narrow to hold its greatly increased body of water, overflowed its banks, and the damage caused by this overflow alone would have been large. But there was more to come, and the results were so appalling that there lived not a human being who was likely to anticipate them.