Like so many stories about safety advancements, this one starts with tragedy and death.

Just before 7:30 a.m. March 26, 1912, there were 91 men in the Jed Coal and Coke Co. mine in Jed, W.Va., when an open flame ignited flammable gas and caused a massive explosion.

Only 11 men survived.

The number killed sets the Jed Mine disaster apart, but it wasn't the deadliest. That distinction belongs to the Monogah Coal mine disaster in 1907, which claimed 362 lives.

Mine disasters — accidents in which five or more were killed — became shockingly common in the early 20th century. Between 1876 and 1900, there were 101 disasters, and that climbed to 305 between 1901 and 1925, according to the U.S. Mine Safety Administration.

In 1909, the year with the most coal mine disasters, there were 20 accidents. In 1910 there were 19, plus six disasters in other kinds of mines.

But the Jed disaster can be thought of as a kind of turning point because of what it inspired.

John T. Ryan Sr., a mining engineer who worked for the U.S. Bureau of Mines, was shocked by the loss of life that day in 1912 and it gave him a thought.

“If I could spend my life doing what I can to lessen the likelihood of the occurrence of such terrible disasters, I shall feel in the end that my life had been well spent,” he later said, according the website of MSA Safety, the company he founded in response to the explosion.

Ryan and George H. Deike formed what was then called Mine Safety Appliances, and to help keep miners safe from explosions, they reached out to an American icon.

The company is headquartered in Cranberry Township.

Ryan and Deike contacted Thomas Edison, best known as the inventor of the incandescent light bulb, but also responsible for the movie camera, the phonograph and hundreds of other lesser known items.

Edison had been working on a rechargeable battery since the turn of the 20th century and had created a relatively portable battery pack that was reliable and durable.

The original goal of Edison's battery was to power electric cars. In the early 1900s, when he was developing the battery, electric cars lead the market, but by the time he'd perfected the design about 10 years later, gasoline had won out over electricity.

Despite the change in the market, Edison's battery would find lasting success in other niches. Because of the design's durability and long life, the batteries would be used as a power back up for railroad signals as well as the source of illumination for MSA's first product, the Edison Safety Cap Lamp.

When Ryan and Deike approached him, Edison was something of an American institution. Never shy about promoting himself and his own work, he found celebrity in the 1870s when he invented the phonograph.

Far different from the records used today, Edison's invention recorded and played back sound using a cylinder made of tinfoil. The sound quality wasn't great, and the cylinders would deteriorate after being played just a few times.

That didn't matter. It was the first time people had ever heard recorded sound and they loved it.

Ever a restless mind, Edison quickly moved on to other ideas. By 1879 he had perfected the first commercially viable incandescent light bulb.

But what good is a light bulb without electricity to power it? Edison's next venture was creating commercial electrical distribution, and by 1883, his first venture, in New York City's financial district, had more than 500 customers and was powering more than 10,000 lamps.

By the late 1880s, Edison's efforts were focused on entertainment again, with the development of both improved phonographs, including a switch to the discs still used today, and the movie camera.

By the early 1890s there were Kinetoscope parlors, featuring single-person peephole style viewers, showing Edison motion pictures.

Like so many of Edison's inventions, the electric cap safety lamp he developed with MSA was a mix of old ideas and new innovations.

The first safety lamps, designed to offer some illumination that wouldn't ignite an explosion while also serving as a warning for the presence of methane or other dangerous gasses, appeared about 100 years before the Edison cap lamp.

English chemist Sir Humphry Davy found that wrapping a metal screen around a flame kept the heat low enough to not ignite flammable gasses. Further developments would include glass and a metal cover, both designed to protect the flame from gusts that could extinguish it.

But safety lamps were even dimmer than the other lighting methods available at the time and they couldn't be mounted on a cap. Many miners resisted using them, fearing they would earn less money, since they were paid according to the amount of coal they dug out.

Instead, in the early 1900s, many miners were still using cap lamps with open flames, usually carbide lamps, which used a mixture of calcium carbine and water to create actelyne gas, which was then burned. Such lamps had the advantage of producing a bright light, but had the disadvantage of setting off methane or other flammable gasses.

Ryan and Deike wanted to change that and they believed Edison was the man to help them do it. After all, he'd brought the electric light to the world in the first place.

While electrification was growing fast in 1915, the cost of installation and remoteness of most mines meant any lighting solution would need portable power.

The end result would combine Edison's best known invention, the light bulb, with one of his later, more obscure ones, the rechargeable battery. The concept would be exactly the same as when the first miner attached a candle to the brim of a hat, but the execution would be so much safer.

The battery pack would attach to a belt or backpack and offered six candlepower of light for 12 hours. When the miners' shift ended, the packs would be recharged and they'd be ready for the next day.

The U.S. Bureau of Mines, created in the wake of the 1907 Monogah Coal mine disaster, approved the lamp in 1915, and adoption was quick.

It can be hard to grasp exactly how much this invention changed mining safety, but the effect was enormous.

In fact, Edison, who has more U.S. patents — 1,093 — than anyone else, said the cap lamp might have been the invention of his that did the most for humanity.

Over the next 25 years, the number of coal mine disasters plummeted. Between 1926 and 1950 there were 147, compared to 305 for 1901 to 1925.

Mining was still — is still — a dangerous job, but the new light helped make it safer.