Ok, who let the undergrad pilot the awesome-bot?
The Autonomous Benthic Explorer, nicknamed ABE (but sounds kinda like Autobot), was a truely independent research sub operated by Woods Hole Oceanographic Institution. Meaning? Well, it was unmanned and un-tethered to its launching ship, meaning it could explore the ocean all on its own.
ABE was on its 222nd dive, exploring the Chile Triple junction, on Friday and was lost. Oh yeah, its the 'one last job' cliche. And so poor ABE lies in a watery tomb somewhere off of the Chilean coast.
Here's the story link: http://blogs.nature.com/news/thegreatbeyond/2010/03/_awesome_underwater_robot_lost.html