Since Swedish waters are not exactly a center of pirate activity I suspect there is an inside angle to this. I also suspect something must have been on board more valuable and less bulky than timber.
This smells like a black operation.
Just as a “what if” scenario, consider the sequelae of a several hundred megaton bomb explosion off the Canary Islands.
Along with a rather impressive tsunami type wave from the bomb, one of the Canary islands may ‘calve’ a chunk of submerged land sufficient to cause a wave of more than Biblical proportions to hit the US Eastern seaboard.
Other possibilities include fault line tension releases, and the associated negative impacts of population centers near said fault lines.
Not Kewl!