As a retired submariner, it pains me to hear of this.
Initial reports are that while 15 sailors aboard the USS Hartford were injured, none of the injuries were serious. If that is the case, then that is the silver lining in the clouds.
Seems like there has been a significant increase in the last few years in the number of submarines involved in collisions of one sort or the other.
Keep these guys in your prayers, if you do that sort of thing.