Who blew up the NordStream pipelines?, page-102

Pigs are sent into pipe lines constantly, they are tools for internally measuring / checking the pipeline. When ROV's are deployed in the area, it will likely indicate that the explosions eminated internally. If this is the case, then it will be apparent that pigs with explosive charges were sent down the line from the Russian end. Whom in Russia has done this, at this stage is speculation.