Had a vehicle operation related close call today. Getting ready for the holidays we were hanging holiday lights in our radio room. Of course we couldn't complete the job without having to use something from the rig. We used a small step ladder from the engine to hang the lights. Of course the newer firefighter was asked to get it from the rig. In doing so left the compartment door open which was on my side. I was unaware he was going to leave it open as we never should. In the process of hanging the lights we got a RES FA and left w/o the ladder. Having walked to the rig I did not notice the compartment door open since it was a top piano hinged door. While pulling out I noticed it and stopped, shut the door averting a disaster. I have gotten into the habit of always checking my mirrors pulling out looking for anything unusual. Thank God I have gotten into this simple habit. I have seen two bay doors and the entire front of a fire house destroyed because of this very same thing. Two apparent things went wrong: a compartment door was left open and the rig was walked away from leaving the door open and two; walking to the vehicle it was not noticed enroute to a call. One thing did go right: It was noticed before leaving the station. Please learn from this. No matter what warning devices we put in place, this happens all the time. Just be careful and take your time pulling out of the station, that extra second could save your butt.