I only have 1500 population now. I'm trying to reach high density first and give them everything they need, but they are telling me that "There are too many injuries". I have a clinic which is never full with 3 ambulance cars on the opposite side of the road so I don't get it. How can this be solved?
Education is the key here actually. It will lower the chances of your sim's getting sick or injured as well as decrease the amount of power/water that they will consume. It does not matter the level of education but you should be aware that anything above a high school will affect your industrial production.