A Bucyrus steam shovel, a modern piece of equipment, symbolized a new style of mining in the copper camp – Phelps Dodge had just begun open-cut mining operations on Sacramento Hill.
The decision to dig the ground out instead of tunneling into it altered the labor, the mechanics, the landscape and ultimately the danger of mining in Bisbee.
Until then there had been no mass mine disasters in Bisbee. The terrible cave-ins and fires that took scores of lives in other mining areas – the copper camps of Butte, Montana, and the upper peninsula of Michigan – did not happen in Bisbee. The largest single underground mine accident, terrible as it was, caused two or three deaths.
Part of the reason was the stability of Bisbee’s hard rock underground and part was because the men often worked in pairs well away from other crew members.
But beginning with the new open-cut work on Sacramento Hill, a whole series of explosions caused disaster in 1918.
Sacramento Hill formed a rectangular mountain running east and west at the end of Mule Gulch. Exploratory work determined a rich mineralized zone and the company decided to strip the mountain to reach the copper. The operation, one of the earliest open-pit mines, required the purchase of specialized equipment, including seven Bucyrus steam shovels and 15 locomotives. In addition, a 3,000 ton concentrator was built nearby.
The company recognized the danger from the enormous and unpredictable blasts that removed the earth and from the attraction of the new and never-before-seen steam shovels. Guards were placed on nearby roadways in Jiggerville, Upper Lowell and on Naco Road.
Newspaper articles implored people to stay off the hill and to listen for the three short blasts from the steam shovels and locomotive that signaled an explosion was being set off.
Despite the preparations, on the afternoon of January 10, 1918, two simultaneous explosions rocked Bisbee. When the smoke cleared, four men lay mangled and dying, eight others were bloodied, dazed and frightened in Bisbee’s worst mine accident.
Three thousand pounds of blasting powder had ignited prematurely, and no one expected it. Three men from the engineering office had been walking about with surveying tapes and tripods, while others filled holes with powder and attached electrical devices. Suddenly the earth rose up amid a deafening noise and the air filled with powder, fire and rock.
The force of the blast derailed a 100-ton steam shovel working nearby. A coroner’s inquest failed to find the cause of the explosion and left blame for the accident unresolved.
Unknown to the company, a third hole filled with powder remained undetonated. Nine days later, taking what all thought were the necessary precautions company powder men set off another charge.
A shower of rocks and boulders unexpectedly rained beyond the safe area. Rocks dropped on a barber shop in Johnson Addition fracturing the skull of a man having his hair cut. A worker 1,300 feet from the blast was killed when a boulder smashed his head. Others narrowly escaped injury, and houses on both sides of the hill were hit by flying rocks.
The company issued more warnings and held safety meetings. Despite their efforts, on March 26, another premature blast killed two men and injured eight.
The Bisbee Review reported the company “at a loss to establish the cause of the explosion.”
The accidents continued for the remainder of the year – in all, 11 men were killed on Sacramento Hill and many more were seriously injured.
The Phelps Dodge annual report for the year reads: “With the additional precautions being taken in the handling of explosives and with the strict safety regulations that have been put into effect it is hoped that the present year may show a material improvement in this regard.”
The safety program finally paid off. In 1919, there were no deaths on Sacramento Hill. Sacramento Pit, as the huge cavity became known, produced 9 million tons of ore. Twenty-three million tons of earth were removed to get to it, which formed a pit 7,000 feet deep.
Mine production stopped in 1929. Today, the bottom of the Sacramento Pit is as far below the townsite of Bisbee as Sacramento Hill was once above it.
Photo courtesy Bisbee Mining and Historical Museum; research by Tom Vaughn. ©Arizona Capitol Times.