I've hesitated to comment here because some of you are quite insufferable.
My family had a pitbull-lab cross for about 8 years. He was a handful, but a nice dog. no incidents. Our kids were maybe 7-8 when we got him, I'd have to do the math.
He was so strong. My kids couldn't even walk him on leash. He was leash trained, but sometimes dogs are just dogs and they're going to do what they want, you can't reason with them.
Anyway, I was always against breed bans, but my opinion has changed. This is actually the video that persuaded me on banning bully breeds in the city. It's quite awful, and I don't remember how I came across it, but it showcases how strong pitbulls are, and how dumb their owners can be.
In case you don't want to watch, a pitbull who was leashed, has grabbed on to a golden retriever's leg, and just won't let go. They don't show what instigated it (the golden retriever could've been a dink for all I know) but it doesn't really matter. Nobody had control of that pitbull, including the owner.
They don't belong in the city.