Are reffering to loosing a colegue?? Did the person pass away due to natural, unnatural causes or while on duty??
There is no text book to tell you how to deal with this. Yes, i had it once before (Other who have passed away were not as close as this person, i knew who they were, but did not know them personally). It was bad, bad bad. We (Another ALS and myself turned out to one of our classmates who passed with us) turned out to a MCA on the border of our areas. We came across some other accidents and got the call from our scene safety vehicle, that on of our fly cars was in a MCA.
Everything you know and are goes for a ball, you just want to get there. On arrival there was a well known (to the EMS, and a good one to have around) off duty ER Dr. who came across the accident. He auctally had to hit me hard against the head at one time and said: "Do the best what you do best". Just to proove that we are all human, 3 days after, he told me that he did not have any equipment with him, and only realised long after that there was a fully kitted ALS fly car with equipment inside (the one they were travelling in). The end result was not favourable, and she passed away two weeks later. Going to full honours funeral did help a lot, and we could some form of closure to the whole episode. Look for support from your friends and family, and your peers. Do not be affraid to seek professional help, we are not "Bulletproof".
FIY, there was another incident, exactly a year later on the same day, almost to the date. There where a lot of similarities, such as: An ALS fly car, same Paramedics treating on scene, same Heli crew, same destination hostpital, same outcome two weeks later...