Holding train where?

Most of the time when I am on BART, I am doing something on my phone like looking up news, learning the latest celebrity gossip, or listening to music.

I am not really paying attention to what station we are approaching.
 

About two weeks ago, there was a broken down train at Embarcadero and all trains were delayed by 15 minutes, while they cleared the tracks. My train was stopped at 19th and 12th Street stations in Oakland and again at West Oakland station. For a brief moment, I thanked my lucky stars that I wasn't stopped in the Trans Bay Tube. I've heard of evacuations that require riders to get off the train while in the tube and journey out on foot. Ugh.
 

I've ways been curious about what The Tube looked like from the outside: you know being that it's under water and all. Are there starfish and sea creatures feeding around the tube? Are sharks lurking around because they can sense human flesh inside? And, is there a diver under there on a regular basis patrolling for leaks or cleaning the algae off?

 

Curiosity and more importantly, urgency to know more about my fear of being stuck in the tube forced me to look up information on this. To tell you the truth, unless I am missing something, there is not a whole lot of live pictures of the tube. Perhaps this is self preservation because it would freak eveyrone out to know what the outside of the Tube looks like under water. If you know of a site that would share this, send it my way...

Here is what I did find, pretty interesting that BART was the inventor or the submergable tube and it has since been used in other countries.