Help with recent movie *SOLVED* TY!

Hi!

I think this movie is recent, last few years, but I can't remember the name! What I remember is:

There was an accident in a lab, an explosion or something, and a lot of people died, but they appear as some kind of ghosts, doing the things they used to do, everyday at the same time and place, and them just disappear, and them the next day is the same.
Authorities keep saying that is always the same ghosts, but each day there's more of them.
I remember a scene where the main couple of the movie goes into a tunnel or something, and it's a very beautiful scene with lots of ghost fishes, and they try to count how many fishes and the guy says that in the beggining it was only a few, and now they can't count because there are too many.

Something like that, I remember a few more details, but I hope this will be enough for the gurus here!

Thank you!!!