Well, DAMN!
But, it does happen, one way or the other, from time to time. Ie, Jessica Savitch,
softball in North Dakota, Port Isabel causeway (in a moment on that one).
A car or a space flooding is probably one of the most terrifying, unknown things to most people, especially in knowing what to do, getting out.....ESPECIALLY with the dependence most have on technology these days. Probably didn't help with how the dog was reacting.
The causeway at Port Isabel would be even worse because an elevated road way just suddenly disappeared and one drove off into blackness. It is similar to this in that all the electronics that we depend on would be gone upon hitting the water. In the boat ramp case, it's because of the flooding; with the causeway, because the impact destroyed them.
The causeway had an additional factor though; the impact triggered the airbags (I attended a DPS briefing on that disaster).
Other factors to complicate the issue. One can't open doors against external water pressure (until the inside equalizes). It probably could be pitch black (their cell phone might have been the only light).
Finally, remember that people in that situation are in a PANIC and probably can't think of one or two thoughts. Ie, on a side point, I was told that some firing a pistol in defense won't be able to think about doing more than one or two actions, so if you are using a 1911, have it cocked and on safety or not cocked, but not uncocked and on safety because in that moment of panic, one can't think about doing two things to arm it.
Tragic.