These days “asbestos” is a dirty word, but there was a time when this miraculous heat-shielding mineral did it all, from insulating pipes and plaster, to fireproofing, to sound absorption. Before it was tied to health problems, asbestos was a routine part of construction in the 20th century, and the construction of Pittsburgh’s historic Schenley High School was no exception. Years after it was deemed uninhabitable because of asbestos, Schenley continues to languish. But in its heyday, the school was considered cutting edge.

The towering wood-paneled doors to Pittsburgh’s Schenley High School swung open for the first time in October 1916. Back then, architect Edward Stotz got tongues wagging by designing the first high school in the country that cost more than $1 million to construct. The three-sided, three-storied limestone edifice is terraced into a hillside and peers down Bigelow Boulevard, just blocks from the University of Pittsburgh. The interior is illuminated by two brick-lined atriums, and its lavish facilities include classrooms with oak moldings and 15-foot ceilings, a greenhouse, and a 1,600 seat auditorium. In the decades to come its alumni roster listed famous musicians, athletes, and artists, including Andy Warhol, among its graduates. By 1986 the school was added to the National Register of Historical Places.

But today Schenley’s classrooms are dark. Through the windows it's possible to see chairs and desks stacked on top of each other, gathering dust. Below the six ionic columns that frame the name “Schenley High” in stone, parts of the façade are beginning to crack, and dead leaves pool in the recesses of the entry pavilion. In 2007 pieces of plaster began to fall from those lofty ceilings, and in 2008 the Pittsburgh School District deemed it unsafe for students and staff. The school was closed, both because of crumbling plaster and asbestos contamination.

Mark Banister is the Assistant Director of Environmental Health and Safety at Carnegie Mellon University and resident asbestos expert. “It’s a naturally occurring fibrous mineral, mined out of the ground like iron ore, or coal or anything else,” she said.

Banister likened it to a down coat. “The down coat is very light, but it insulates you very well because of the surface area that’s produced by these very fine fibers, and that is the insulation property.”

Asbestos looks a little like the inside of a Butterfinger candy bar. In bulk, it’s about as hard as a finger nail, but it’s made up of long thin crystals that can easily be crumbled down into fibers. Six naturally occurring silicate minerals make up asbestos, something called chrysotile is by far the most common.

Banister said the same fibrous, crystalline structure that makes  asbestos such a great insulator also makes it dangerous.

“When it becomes airborne, the fibers deposit in your lungs. Your lungs recognize this as a foreign object, and they put scar tissue over the top of it as a defense mechanism, but now you have a lung full of scar tissue and it does not oxygenate your blood like the other parts of your lungs should be doing,” Banister said.

The link between asbestos and health problems first gained attention in mining towns in the early 1900s. Then, in the 1940s, asbestos was linked with the cancer mesothelioma. But it was not until the 1970s, when the newly created Environmental Protection Agency looked into the effects of the mineral, that it began to be regulated. New guidelines forced schools to monitor, manage, and abate asbestos to make sure students were safe.

Abatement is the process of removing asbestos from a site while keeping all the microscopic fibers from floating off into the air. Mark Banister said it can take a week for a room, or months for a large building.

“Looking in my office here: if we were to abate, right outside my door we would have a decontamination chamber, that the workers would go in. They’d take off their clothes in the first thing, there’s a shower in the middle and they would put on their suits and they would do this work in a completely enclosed area,” Banister said.

That is on top of all the specialized fans, filters, and equipment needed to keep people safe during the work. It is a big undertaking, and Schenley High School was no exception to the new rules.

“From the outside it looks like a magnificent building, but when you get into the interiors of the building, you find the true magnitude of the situation there,” explained  Dan Davis, who worked for one of the environmental engineering firms that studied the asbestos situation at Schenley.

Like in most old buildings, asbestos was everywhere. Davis said it lines the ventilation system, is embedded in floor tiles, insulates pipes and ductwork, and was thought to be mixed into the plaster that was falling from the ceiling. Removing all of that asbestos is no small task.

“I get a call in September before the building closed from a teacher who said, ‘You have to come and see this. It’s disgraceful what people want us to teach in,’” recalled Bill Isler. Isler is a member of the Pittsburgh Public Schools’ Board of Directors, and was president of the board when they voted to close Schenley.

“We knew the building was crumbling and we knew it was going to cost a tremendous amount of money to retrofit it,” Isler said.

It turns out Schenley’s plaster only contained trace amounts of asbestos. Engineer Dan Davis explained newer, more accurate technology reveals that the plaster holds 0.25 – 0.5% asbestos. The real danger to Schenley’s occupants was the chunks of plaster crashing down from 15 foot ceilings.

The bill for removing and replacing the plaster, as well as  repairing myriad maintenance problems, installing a new heating and cooling system, and integrating the electricity and internet needed for modern classrooms was astronomical — costing anywhere from $55 million to more than $80 million.

Isler said they had a choice to make. “In the middle of a recession do you spend that money or do you make do with what you had?”

Davis agreed, and noted that building a brand new school would cost tens of millions of dollars less than restoring and modernizing Schenley. “You've got to look at your costs. Your population is decreased in the city of Pittsburgh with school students […] Schenley was beautiful. I’ll admit it was beautiful the way it was set up. But for a long-term situation, could they invest that much money?”

They decided they could not, and in 2011 the final class of students who began their education in the original building graduated from a different school building.

Davis said the debacle at Schenley prompted parents and the school district to take a close look at the condition of its other school buildings. “That’s where I went next after Schenley, was to review those buildings monthly too, and if there was an issue we took care of it real quick. So they became proactive in their other buildings to make sure nothing did happen like Schenley was.”

Once held up as a model for high school innovation and design, Schenley is now held up as a cautionary example of what can happen when a school is not properly maintained. Today Schenley is in limbo. The school board has put its sale temporarily on hold and city council is searching for ideas for its reuse, but whoever takes over the building will have to remediate and renovate, replacing the asbestos with new materials like fiber glass. But despite the price, many in Pittsburgh say Schenley is worth saving.