As far as I know valves were shut quickly. The big leak was a result of remaining gas (under pressure?) between the valves that could escape. It was a lot, as the pipes run for 100s of km under the sea, so even with valves shut there was just a lot gas in the pipe.
Is nord stream still leaking? I forgot about this.
As far as I know valves were shut quickly. The big leak was a result of remaining gas (under pressure?) between the valves that could escape. It was a lot, as the pipes run for 100s of km under the sea, so even with valves shut there was just a lot gas in the pipe.