Sharks, cats, possums, bored rural people with shotguns, a rockslide in the wrong valley in South America (there's pretty much just one pass that all east/west SA traffic passes through). All of these are things that occasionally take out either comms, or data centres on a semi-regular basis.
"How Google Stops Sharks From Eating Undersea Cables":
https://www.forbes.com/sites/amitchowdhry/2014/08/15/how-goo...