A massive nuclear test waste dump in the Pacific is leaking radioactive material into the ocean.
A 50cm-thick concrete dome is all that stands between 85,000 cubic metres of soil mixed with radioactive waste and the people of Enewetak Atoll in the Marshall Islands.
Runit Dome - or "the tomb", as locals call it - contains the waste leftover from dozens of atomic tests carried out by the US in the mid-20th century.
But according to a new report from Australia's ABC News, climate change is taking its toll - water is penetrating the dome.
Also, the bottom isn't lined at all. During its nuclear clean-up in the 1970s, the pit - itself formed by an atomic blast - was deemed too pricey to line the porous seabed with concrete.
"The bottom of the dome is just what was left behind by the nuclear weapons explosion," Michael Gerrard, the chair of Columbia University's Earth Institute told ABC News.
"It's permeable soil. There was no effort to line it. And therefore, the seawater is inside the dome."
People living on low-lying atolls in the Pacific are destined to be some of the first victims of rising oceans caused by climate change, and now they face nuclear contamination on an unprecedented scale.
So many of the atolls are unsafe, even this many decades later, locals have resorted to imported food like spam and other processed goods. They're not allowed to eat or export their own food.
And the problem's not going away - the fissile material left behind has a radioactive half-life of more than 24,000 years.
"This could cause some really big problems for the rest of mankind if all that goes underwater, because it's plutonium and cement," compensation fighter Jack Niedenthal told ABC News.
"It's like this big monument to America's giant f** up."
It's hardly a silver lining that if the dome cracks completely open, it might not actually make things any worse - they're that bad already, says Mr Gerrard.
Enewetak Atoll sits west of the more famous Bikini Atoll, where only half as many atomic tests were carried out. Between the two of them, the explosive potential of the 67 tests was equivalent to around 7000 Hiroshima-sized bombs, the Guardian reports.