I saw a post on Africanhunting.com by a hunter who is stuck in Joberg due to his return flight to the US being cancelled due to a lack of fuel at the airport. Here's a link with so info. on the subject.

https://simpleflying.com/unite...sburg-fuel-shortage/

That’s pretty bad, hope they get it sorted quickly. We were leaving there once when they cancelled a flight due to the airline not paying for fuel, mot United.