Need to remember that some cables have common points where they cross over and share fate, identified as shared risk link groups (SRLGs). Good engineering and design practices involve ingesting detailed fiber routes in GIS databases (kmzs in some cases) to identify these and build diverse paths. Every now and then sometimes people get surprised by what is documented isn't what's in the ground (this is a bigger problem in urban/metro locations). Example where fiber goes under the same sidewalk, transitions from aerial to underground, etc.

Could this vessel be the cause?

"Suspected Internet Cable Spy Ship Operating In Americas For Over A Month"

https://www.forbes.com/sites/hisutton/2019/12/01/suspected-i...

Interesting that the word "cuts" is perhaps-intentionally ambiguous.

I wonder if this was detectable undersea fibre damage, or just Iran/Turkey switching off multiple shore stations at once?