Visible crew/equipment: At the scene of the plane that hit the building, after the explosion, when Foam 10 arrives there's a closeup of the firemen using the foam tubing, and behind the doorway one of the 'firemen' kicks the foam tubing, but notice that he's not really a fireman, he's actually a crew member who's wearing a turnout coat, though he's also wearing jeans and work boots.
Visible crew/equipment: When Mr. Laurents visits Station 51, as the guys stand up the actor's T-mark is visible on the floor, between DeSoto and Chet, just before Chet promptly stands at his mark.
Visible crew/equipment: After Johnny and Chet begin their arm wrestling, when dispatch drops the tones, there's movement at the front seats of Engine 51 where the camera is located, while Captain Stanley is at the radio base station and Mike is putting on his turnout.
Visible crew/equipment: At the structure fire at an abandoned building, when Engine 164 arrives, we can see the reflection of the location's array lighting in the driver's side window.
Visible crew/equipment: After Johnny reads the note from Mr. Laurents, which he left with the package of money in the fridge, Captain Stanley walks over to the counter, where the actor's T-mark is visible on the floor.
Answer: It is standard practice to wet down driveways so that they stand out in a long shot.
stiiggy