When Merced Guimaraes found piles of human bones under the floor of her Rio de Janeiro house during a refurbishment, she thought she'd stumbled upon evidence of a serial killer.
Guimaraes even worried that police would "think I killed them." The "terrified" builders doing the work fled.
What she'd discovered, though, was something more terrible: her house sat on the remains of many thousands of African slaves -- the biggest slave cemetery ever found in the Americas.
That accidental brush with history in 1996 transformed Guimaraes, an energetic, cheerful woman who is now 60.
She ceded control of her small family business to her children and instead of trying to build a comfortable home, set out to turn the property into a museum. She wanted to create "a living testimony to a crime against humanity."
In 2005, she finally succeeded, opening the Institute of New Blacks. The exhibit, centered on a large pit crammed with yet-to-be exhumed bones, had attracted 70,000 visitors by last year, with the traffic on a rapid upward curve.
Despite that success, the institute is close to shutting down.
Lack of money is the obvious reason.
A government subsidy has been cut amid fierce recession and the hangover of hosting the Rio Olympics, leaving the institute struggling to pay electricity bills or even to buy cleaning supplies.
But ultimately the problem, Guimaraes says, is deeper: Brazilians simply don't want to confront their "national shame."
- Hidden history -
Ten times as many slaves -- almost five million in all -- were shipped to Brazil as to the United States before the country abolished slavery in 1888, the last nation in the Americas to do so.
That mass movement left Brazil with the largest black population outside Africa and a rich musical and cultural heritage. Yet the dark side is rarely discussed and even less effort is made to honor the victims.
Rio's old port area was once the heart of the slave business. Ships docked there, so-called "new blacks" were quarantined, and the survivors were sold.
But with the physical reminders mostly gone or buried, the history has been lost to all but the specialists.
The finding of what are believed to be tens of thousands of human bones under Guimaraes' house -- and also the 2011 discovery nearby of the Valongo slave ship wharf -- have not been enough to cure that amnesia.
Plenty of schools and scholars visit the institute, but it's barely known to the general public, a pinprick on the Rio tourism map. Ambitious plans for expansion to a three-floor facility look like a fantasy.
"The Brazilian government has and never did have any interest in these questions. The problem isn't today's financial crisis. This has been going on for years," said Antonio Carlos Rodrigues, the museum's general secretary.
"It's racism," Guimaraes said.
For years, Guimaraes funded the project with her own business, a pest control company. Then in 2013, a Rio urban renewal fund established ahead of the Olympics came to her help, covering the approximately 9,000 reais ($2,800) monthly operating costs.
This year, amid near bankruptcy in the Rio government, that aid was suddenly axed, leaving the institute with only enough funds to survive until July, Guimaraes said. Then "we'll have to close for an indefinite period."
One obvious solution to the funding problem -- making people pay for tickets -- is unthinkable, Guimaraes says.
"It's not right to charge people to see a crime."
- 'Children of the house' -
Visitors to the institute get to see a short documentary film and artefacts, like a branding iron used to mark newly purchased slaves. But the bone fragments, tibias and broken skulls lying in the dirt are the real draw.
The mass grave is documented to have been in use from 1769 to 1830. But no one really knows how many people lie there, with conservative estimates at around 50,000, according to archaeologist Reinaldo Tavares, volunteering from Rio State University.
Bones were generally burned and crushed to make space and cataloguing is "extremely slow," Tavares said.
Last week he found a complete skeleton of a woman. She lies stretched out, her mouth open, as if in a silent, endless cry.
Leticia Valdetaro, a 12-year-old girl who came on a school tour, called the sight "unreal."
"I feel really bad, I feel ashamed," she said. "This happened in our country."
But whatever happens to the museum, Guimaraes will never abandon her unplanned housemates.
They were tossed away like "garbage," she says, wiping a tear from her cheek. But to her, "they're children, children here in the house, in our house."
