One is maybe an accident.
Now could there be seismic activity involved? Well, if there had been. But there wasn't.
My money is on sabotage but the question then becomes who has motive and capacity to pull it off? It certainly wouldn't be Russia; while they're capable there's no motive. They'd like to sell gas, of course, and can't without the pipes to deliver it.
This is truly a "black swan" sort of event, in that now its precluded for Europe and Russia to agree in some way to turn the pipes back on and deliver the gas over the upcoming winter. Without a means of delivery it doesn't matter what you want to do; you simply can't do it. And while I'm sure the damage can be repaired that's not a "few day" or "couple of weeks" problem in a circumstance like this.
Very bad things are likely inbound for Europe this winter, all on the basic fact that all modern civilization progress has come from carbon-based fuels. I don't care if you like this or not; it's fact. All the WEF-maven sorts fly around in planes fueled with..... carbon. Equally-seriously modern agriculture is absolutely dependent on this, in particular natural gas which is the major feedstock for modern fertilizers, and European farming uses far more of them on a per-acre basis than we do in the US. It's how they get their yields and without them, well...... yeah.
Never mind industry which, if forced to shut down cannot simply be turned back on. Plants that run on a continuous basis frequently have "hot sections" that, if cooled, require weeks or months of refurbishment and a graduated restart procedure; it is not a "light switch" sort of operation.
Be careful thinking this is no big deal folks -- you're likely very wrong about that.