Visible crew/equipment: At training center, after 18's guy falls into the trench with the sulfur trioxide, as they're removing his turnout coat just as Roy opens the drug box, seen behind Marco are four crew members who are near the tanker with the sulfur trioxide, past the trench.
Visible crew/equipment: When Engine 51 and Squad 51 arrive at the training center, Captain Stanley opens the door then steps off the engine while Chet climbs down from the jumpseat, and the location's array lighting is reflected on the door's window.
Visible crew/equipment: When the man, who walked in with his daughter, has a heart attack at Station 51, while he's lying on the floor in the apparatus bay we can see the top of the set, the part of the ceiling that's incomplete.
Answer: I believe you are speaking of the old man, Mr. Wilson. He's played by J. Pat O'Malley.
Bishop73
Correct, it was J. Pat O'Malley...he also played the grandfather with his grandson when their rocket exploded, and also played "Old Bill" in the episode with Ann Prentiss, where Gage saves the little girl from the burning tree house, and her mother falls in love with him.