Hello,
I just recently built my first bathroom and within 2 game days every toilet has a red wrench on it. I figured out I needed to hire maintenance personel but it seemed like 2 game days was a bit short for brand new items to start to break,
This also happened with gate seating. Passengers were going to different terminals to sit and I couldnt figure out why until I saw the red wrench icon on the seating as well.
Love the game, just takes a while to figure out the quirks