[usrusr]

What are the chances that they break in close proximity spacially, but not temporarily? (I'm assuming that it would be headline material if the lines had disconnected within minutes)

Tangent: an attacker trying hard to provoke that kind of accident would likely not have a very fast success feedback. "Let's try once more, for good measure"

[crote]

Still pretty decent, given the right circumstances.

For example, the 2011 earthquake in Japan resulted in damage to 7 cables[0]. But it wasn't the quake itself which instantly broke all 7 cables - they were destroyed by underwater avalanches triggered by the earthquake. Avalanches can occur hours after a seismic event, and some underwater avalanches go on for days.

I highly doubt that's the case here, but if you're asking about chances it's not as unlikely as you'd think!

[0]: https://www.theverge.com/c/24070570/internet-cables-undersea...