Two pilots were on board. Apparently there were issues with the ship’s propulsion system at last inspection. My money is on a mechanical issue; if not, this was a monumental fuck up by the harbor pilots and/or the crew.
edit: lol, I am pleased with how this comment has aged. Yes, it was a power loss. Quick thinking and action saved lives. Bravo. Now it remains to be seen whether deferred maintenance or similar negligence were to blame; if so, people need to pay up.
That sucks and all, but at least we can still have guns!