When I was very young, my family lived in an area like this. My mother never let me catch the bus, ever. My parents drove me to and from school (the school wasn't much better). I was not allowed to play outside, and all playdates were at our home unless my parents took me directly to the friend's house, and only if they knew the parents well enough to trust they would also keep us inside instead of playing in the line of fire.
Even my mother avoided being out and about as much as possible. She had problems with some men in a house by us, and had a close call. As soon as was possible, we moved and never looked back.
Bottom line, shelter your child. Even with that, you can't guarantee safety in a place like this. We had a break-in while we were all home, and shots fired at the house all the time for no reason except that our house was in the way of something going on the street that day.
As another suggested, breaking the lease may not be a bad idea in the big scheme of things if it's really that bad. It gets nerve wracking and old very quickly if you have to live in fear and worry that something might happen despite taking every precaution to be safe.
I also agree with the other poster who said to educate your child on what to do if you're not around. Sadly, your child is going to have to develop street smarts. You can't be with them all day. There is the time away at school and other unexpected scenarios. Honesty is the best and wisest possibility. You don't have the luxury of doling out the bad news on a case by case basis. You're going to have to get the facts on the table about street life and dangers, so your child can avoid these situations and people. In areas like that, criminals and dehornes have no love of children. They exploit them all of the time, and have no concern of accidentally hurting a child when they fire off guns mindlessly in the streets.
Hang in there.