The Hercules Powder Company near Ishpeming is seen in an undated image prior to the 1921 explosion that did substantial damage to the facility. (Photo courtesy of the Marquette Regional History Center)

ISHPEMING — “In a terrific explosion which rocked the entire city and could be felt in other parts of the county, the lives of four workmen were snuffed out yesterday morning at 10:30 o clock, when the dynamite mixing house and nitroglycerin storage house of the Hercules Power company’s plant at National Mine blew up without warning” (Mining Journal, July 27, 1921)

The force of the blast was enough to shatter windows in both National Mine and Ishpeming and even broke windows in Negaunee as well. “Mining men familiar with blasts and explosions, and who know the difference of the two, realized that it was an explosion that had rocked practically every building. For several minutes after the shock men congregated in the center of Iron street and watched the smoke in the direction of the plant, towards the south. Automobiles began to scurry around picking up passengers who wanted to go to the Winthrop, to the scene of the excitement. In less than half an hour, several hundred Negaunee residents were enroute to the plant.” (Negaunee section, Mining Journal July 27, 1921)

“In less than thirty minutes there were from 300-400 automobiles parked along the highway between the powder mill and the National Mine post office.” (Mining Journal, July 27, 1921) Following explosions in several other structures, an abandoned gelatin mixture house and the spent acid house, the gathered crowd quickly disbanded and returned to their respective cities.

“Just what caused the explosions will forever remain a mystery. There are numerous ways in which nitro glycerine can be exploded, but all evidence has vanished and the only occupants of the buildings in which explosions occurred are dead. It is estimated that over 7,000 pounds of nitro glycerine did the damage. There was no dynamite in the mixing house at the time, the last batch to be made having just been removed and taken to the packing house.” (Iron Ore, July 30, 1921)

While dynamite was much less volatile and therefore safer to use, some mines still needed to use nitro glycerine.

“It was remarkable that the explosion did not result in more fatalities as there were about 100 men employed around the plant when it happened. Several men received minor injuries from flying debris and others were badly shaken up, some being thrown to the ground. One man riding a wagon in the mill yard was thrown from the seat into a clump of bushes about fifty feet away.” (Mining Journal, July 27, 1921)

The dead were identified as Charles Lundin and August Sjoholm of National Mine and Leslie Drew and Claude Tippett of Ishpeming. Both Drew and Tipett were only 18 years old and Lundin and Sjoholm left families behind. While the bodies of Sjoholm and Lundin were found the afternoon of the blast, only pieces of the other two could be found. “As much of the mangled bodies of Leslie Drew and Clyde Tippett, victims of Tuesday’s explosion at the Hercules plant at the National Mne, as it is believed possible to find has been recovered and prepared for burial.” (Mining Journal, July 30, 1921)

Hercules had just taken over the plant at the beginning of June. “On Monday of this week the assets and business of the Aetna Explosives company, which operates a dynamite plant near Ishpeming, passed to the control of the Hercules Powder company. Announcement of the deal was received at the local office a few days ago, but the business will be conducted as usual and it is believed certain that the Ishpeming plant will continue in operation, it being one of the best of the Aetna factories and efficiently managed.” (Iron Ore, June 11, 1921) The plant was located close to the present-day Tilden Mine.

The manager of the plant, C.C. Cowpland, narrowly escaped the disaster by a few minutes. T.C. George, inspector of powder mills and magazines for the bureau of explosives was at the Hercules plant. “The two officials had just left the office and were started on their way to the dynamite house for the purpose of going through the entire plant from beginning to end when the explosion took place. “ (Mining Journal, July 27, 1921)

The man who had driven Mr. George over to the Hercules plant, Mr. Johnson, was still in his car. “Mr. Johnson said that his automobile left the ground entirely and went four feet into the air at the time.” (Mining Journal, July 27, 1921)

Fire also caused some damage. “It was but a few seconds after the explosions that several of the buldings not carried away by the blasts were on fire. The soda storage house, the soda dry and one of the warehouses were totally destroyed by fire, while another of the warehouses and soe of the other structures were damaged.” (Iron Ore, July 30, 1921)

Rebuilding started soon after the blast as explosives were a vital part of the mining process. “Mr. Cowpland announced yesterday afternoon that it will be necessary to discontinue the manufacture of powder until the demolished buildings are replaced and that the plant would probably be going again in about three weeks. There is sufficient stock on hand to take care of the requirements until the plant is again ready for operation and the entire crew will start work today clearing up the sites of the buildings destroyed by fire and replacing them with other structures.” (Mining Journal, July 27, 1921)

“Mr. C.C. Cowpland, general superintendent of the plant, estimates the property damage at about $30,000 (about $441,000 today,) all fully protected by insurance.” (Iron Ore, July 30, 1921)

This was not the first time the plant had blown up, an explosion in 1909 caused damage but no fatalities and an explosion in February of 1911 killed 10 men.