Visible crew/equipment: When the attendants wheel the boy who can't breathe into the ER, then stop at the nurses' station so Morton can have a look at him, there are two white tape marks visible on the floor, one is below the base station's tape recorder, where a nurse first stands, and the other is at the side of the main desk, where that same nurse (behind Dixie) stands a moment later.
Visible crew/equipment: While en route to the structure fire, Mike is driving Engine 51, and seated backwards in the jumpseat behind Mike is Marco, who's wearing a helmet and his turnout, but in the shot from the POV behind Mike, we see the reflection in the rear-view mirror of the grey haired crew member, who is seated facing forward behind Mike.
Answer: It is standard practice to wet down driveways so that they stand out in a long shot.
stiiggy