Back in the 1980s, the Singapore Zoo brought in four male gorillas from Europe and housed them in a spacious outdoor habitat.

However, all four succumbed to a mysterious disease. A post mortem revealed that the gorillas had contracted a rare soil disease called melioidosis, or Whitmore’s disease. Found in contaminated water and soil, the disease infects both humans and animals and has a fatality rate of 40% if not properly treated.

Learning from its mistakes, the Singapore Zoo imported another two male gorillas from the Netherlands in 1990 and placed them indoors with no direct contact to soil. Yet, one of them died from the very same disease a few months later, reportedly due to fine soil being blown in from the ventilation window. The second gorilla was immediately sent back and survived.

The Singapore Zoo received much criticism for its failure to provide a safe environment for the gorillas, considering that gorillas are already an endangered species in the 1980s.

And this is why Singapore Zoo does not have gorillas.

(Image credits: Valentin Jorel)