Its not my feed but maybe the feed provider will see your post.
Seems that "D5" is the primary ambulance operated by Dalton Ambulance Squad. "D5" probably signifies "Dalton Unit 5". EMS calls are heard being paged out to the Dalton Ambulance Squad and D5 was heard going to the scene, and to the hospital with the patient. Possibly the Dalton FD "rescue truck" is sent to EMS calls when D5 is at the hospital.