Air Traffic Control Developmental
Communication Breakdown; Distraction
ATC Issue All Types; Deviation / Discrepancy - Procedural Clearance; Ground Incursion Runway
Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance
Human Factors; Procedure
I was working Ground Control and Clearance Delivery combined from the Ground Control Position.  We had an emergency inbound for runway X which was a Cessna 172.  The fire crew began rolling from the fire house as 4 different call signs: Airport Command; Police Command; F2; and F3.  I also had an OPS14 coming out to assist the emergency vehicles.  I told them to proceed to runway X at their staging areas and they went to the areas they were supposed to go to. The emergency aircraft was the third aircraft to land on X with 2 aircraft taxiing out to [RWY} X.  I initially told Airport Command that the Cessna was 3.5 miles southeast of the airport on initial call.  The first aircraft landed and exited the runway at H4 where there was no emergency vehicles located. The 2nd aircraft to land was a P28A and was planning on exiting H3; where there was a fire truck and an SUV.  The fire truck had to back up to allow the aircraft to exit the runway and this is when another fire truck entered the runway from an access road to follow this aircraft. I noticed the fire truck was following the wrong aircraft and promptly told them to exit the runway and that the next aircraft would be the emergency aircraft; a high wing Cessna. The Cessna landed on [RWY] X with no incident and the fire trucks went back to the fire house with no further assistance.  The Cab Coordinator alerted the supervisor that the vehicle had gone on the runway without authority and I was alerted by the supervisor the next morning when he wanted to listen to the tapes. I would highly recommend that all the emergency vehicles be under one call sign and not 5 calling the ground controller at once.  It adds to the confusing that is already going on with the emergency inbound and it is very unnecessary.  It would have also been nice to know which vehicles were under which call signs because I'm new to this airport and at my last facility; only one vehicle spoke for the entire convoy.
Ground controller reports of a runway incursion due to emergency equipment entering the runway for the wrong aircraft.