Economic/business Clusters have been the engine responsible for much of the Puget Sound region's economic growth for many years. What are clusters? A common definition is" a geographic concentration of interconnected businesses, suppliers, and associated institutions in a particular field. Clusters are considered to increase the productivity with which companies can compete, nationally and globally." Software, bio-tech, medical and aerospace businesses are well known current examples. Markets are not just local for these businesses and the pooling of talent helps all to attract and retain the skills needed.
It started in the northwest with natural resource driven industries such as mining, timber and fishing - and Explosives Manufacturing. The explosives cluster began in 1909 with DuPont opening its manufacturing facility in the company town aptly named DuPont along the Nisqually River and Puget Sound. DuPont provided access to markets via both rail and ship, opening up markets as far south as the Panama Canal and as far north as Alaska. Local demand was also high for mining and logging.
Why focus on Explosives Manufacturing as an early cluster? Safety at these plants was paramount and they also blew up a lot. Part of DuPont's success was 3,200 acres where they controlled everything including access. Yet despite the secrecy surrounding it, we know that the plant had numerous explosions including some loss of life. According to the Official DuPont History, explosion occurred in 1909, 1910, 1916, 1922, 1924, 1926, 1930, 1935, 1936, 1938 and 1947. A ship carrying a cargo of explosives exploded with captain and crew running the ship aground to save themselves, starting a fire on shore not far from today's Narrows Bridge that lasted days. DuPont was a model of workplace safety that permeates the company to this day and yet despite it all, they still had problems.
Other cluster businesses located nearby and likely staffed with some people with experience at DuPont, were not so fortunate and faced big explosions and large loss of life. The J.A. Denn Powder Company operated an explosives plant in Hawks Prairie, just across the Nisqually River from DuPont.

Image courtesy Seattle Post Intelligencer and HistoryLink.org
Eleven people died in this explosion that occurred in 1934 including the plant chemist. Shortly after the disaster, Patrick Kelly, then Director of the State Department of Labor and Industries, announced that insurance rates would be raised for those employed in the explosive manufacturing business.
Another cluster business was established in Frederickson, near Puyallup and current home to a Boeing Manufacturing plant. The following photos of the Columbia Powder Company plant show the aftermath of explosions in 1940 and 1949.

Photo courtesy of Tacoma Public Library, D-10525-2, circa 1940
Four employees lost their life in this explosion when 2,000 lbs of dynamite ignited, blowing the plant to smithereens. The explosion could be heard 30 miles away. Nine years later, an even larger blast occurred.

Photo courtesy Tacoma Public Library, D41193.4, Richards Studio Collection, circa 1949
A family of six who lived nearby was killed in this explosion that leveled a 3 story building and rocked buildings 15 miles away. Dangerous stuff.
Which makes DuPont's accomplishments at their plant even the more miraculous where 2 people perished in explosions during a period that spanned from 1909 to 1975 and during which well over 1 billion pounds of explosives were manufactured. Quite a record.
Footnote: My first job out of graduate school and WSU was with DuPont at their headquarters in Wilmington, DE. It always made an impression on me about how important safety was to the company. I was with the Finance group and about the closest I came to being in danger was when I tried to fix the copy machine. EVERY department in the company was required to have safety meetings.