When someone dies, tragic or otherwise, the standard procedure for their spirit is to leave or become disconnected from their worldly body, take a quick look around, and then proceed in an orderly manner to the nearest exit into the next world.
It is not unusual for the spirit to want to hang out a few days for any number of reasons. They may be upset that they died before they were finished with life. Often they are in denial of their circumstances. It may be something as simple as wanting to comfort their loved ones or to get one last message across to the living. I suspect that some just stick around just to see who shows up for the funeral. Despite the endless possibilities, the point is that in death – as in life, we all find a lot of excuses to not follow instructions.