I think everyone has the same two thoughts the first time, and every time, they drive through an underwater tunnel:
1. How in the world is this even possible?
2. Holy shit, I am fish food if there is a crazy accident or some construction worker got a little lazy with the cement in the wrong spot which causes a tiny leak to become a waterfall.
You can amplify that 2nd thought by a hundred, thousand, trillion when you actually see that nightmare happen in your local tunnel in a movie like countless New Yorkers did in Daylight.
If you ever saw the commercial for Daylight, let alone saw it on the silver screen like I did, you had your head on a swivel about the Lincoln Tunnel potentially turn into an aquarium every time you drove through it. Expected it even. The amount of irrational (or maybe rational) fears a movie with a 25% Fresh rating on Rotten Tomatoes is actually impressive. Daylight won't be placed anywhere near Sly Stallone's Top 10 and made $160 million internationally by riding the disaster movie tidal wave of the mid-90s. But its lasting legacy will be scaring the shit out of every hardnosed Northeasterner that has ever driven through that tunnel (unless 2020 goes full 2020 and reboots the franchise in real life, which would be very on brand for this year).