This info goes with the images above.
For a “very high value target” (like a pipeline) the Mark 18 could be packed with demo and parked next to the pipeline.
Most units like these are modular, so it’s not a big deal to add a meter or so containing an explosive stage in the middle.
If the POTUS ordered the USN to blow up the NS1 & 2, IMHO, this is how it could have been done.
If this happened, quite a few USN personnel know about it. I’d love to read their NDAs. They will probably all be transferred to separate “Ice Station Zebras” where they will not be available for testimony.
Much more info about the Mark 18 “Kingfish” UUV at the link.