Until 1828, few people knew how to ignite anthracite and use it for fuel. That was because anthracite was so compact that no ordinary flame could make it burn. Then, a Scotsman named James Neilson invented the hot blast furnace. The air produced in the first chamber of the furnace was blown over anthracite located in the second chamber. That hot air caused the surface of the anthracite to ignite. Because anthracite was so dense, it could produce enough heat to melt iron ore. It was also plentiful, and a little went a long way, which lowered the cost of iron production. Once the hot blast technique was perfected, anthracite was in demand all over the world. In the United States, anthracite was found exclusively in Pennsylvania. As a result, Pennsylvania's mining industry boomed during the nineteenth century. In the twentieth century, when newer fuels replaced anthracite, the black gold rush ended and most anthracite mines were abandoned. However, abandoned mines still dotted the landscape of Pennsylvania's anthracite country. Towns often used the sites for landfills. Such was the case in Centralia, a small town built directly above a layer of anthracite. When the Centralia landfill caught fire, no one was alarmed because it was so far down in the ground and was contained. They didn't realize that Centralia's landfill was similar to Neilson's hot blast furnace. The trash in the landfill provided the fuel to heat up the pit's air. Dumping continued and the trash burned for weeks, stoking the fire and raising the pit's temperature even more. The hot air released by the burning trash traveled through the empty mining tunnels and into the abandoned anthracite mine, causing the coal to ignite.

How It Spread
Despite efforts to douse the fire with water, the landfill continued to burn. Experts were brought in to help with the situation. Readings of the smoke coming from the landfill determined that burning coal was indeed producing some of the smoke. The warning came too late, though. Local firefighters poured thousands of gallons of water into the landfill, but within a few days the fire would always flare up again. The fire had already started burning into the Buck Mountain anthracite coal seam lying underneath Centralia, and no one could stop it. Between 1962 and 1978, state and federal governments spent $3.3 million on unsuccessful efforts to control the fire.

The Effects
By 1979, large pits in the ground began to open up where the underlying coal had turned to ash. The process, known as subsidence, swallowed roads and destabilized buildings. Pennsylvania Route 61 crumbled despite thousands of dollars spent by the state in 1983 to repair the road. In some parts of town, ground temperatures rose as high as 1,000 degrees Fahrenheit just feet below the soil. Smoke rose from cracks in the ground, poisonous gases escaped, and plants withered. Centralia's gas stations closed from fear of explosions. Though residents desperately wanted to leave, they couldn't. Insurance companies canceled their homeowner policies, and b
anks threatened foreclosure. The residents of Centralia were trapped.

Congress Steps In
In 1984, the US Congress intervened. It appropriated $42 million for the State of Pennsylvania to buy homes from Centralia residents. Congress called this evacuation effort "voluntary acquisition" since the residents could choose not to sell their homes and remain in Centralia. Between 1985 and 1991, 545 residences and businesses were relocated. In 1992, the state government began condemning homes threatened by subsidence and noxious gases such as carbon monoxide. Some die-hard residents remained in Centralia, though. According to the state's Department of Environmental Protection, by 1996 Centralia's former population of 1,100 dropped to 46. The current population stands at around ten.

The Ghost Town
Today, Centralia is an eerie ghost town. The wafting smoke and shifting soil are too dangerous for most to brave. The detour signs on Route 61 give no indication of the troubles in Centralia; most cars just veer around the smoldering town. But for those who are fascinated by the fire, Centralia has become a sort of mecca. Tourists come to stare at the devastated landscape, and conspiracy theorists gather to share their outlandish ideas. Of the visitors, the researchers are the most hopeful. They study Centralia's soil, plants, and animals, and they believe that the effects of the fire will shed light upon the processes that created this planet. Though a terrible tragedy, the Centralia fire may someday lead to breakthroughs in science and technology.

Which BEST explains the impact of the fire on the city of Centralia?
A. The decrease in the availability of anthracite harmed Centralia’s economy.
B. Business in Centralia increased as more people began to invest in the mines.
C. Roads and buildings in Centralia were damaged and required expensive repairs.