As a pit bull owner, I believe alot of attacks, of all breeds are the result of a lack of exercise. You can’t leave an animal with loads of excess energy in an apartment building with no outlet. Combine that with aggressiveness training and it is a recipe for a canine assault.
A travel trailer moved into a space at the mobile home park I stay at when doing field work. They had a big male pit bull they put in this small yard with a 2.5 foot chain-link fence and a dog house. After a while, they put a small just weaned pit bull female puppy in there with him. She was so small I was worried she would be trampled. After a few days they became inseparable and I watched as she lay down beside him and followed him around the very small pen. I walked over to the fence. The puppy was a little skittish, but the big male was so happy to see someone he eagerly wagged his tail. After letting him sniff the back of my hand (keeping it ready to quickly retract if necessary), I reached to pet him. He just loved a scratch around the ears and was anything but mean.
However, I was happy that they moved out after a couple of weeks; two pit bulls in a small enclosure with a short fence was asking for trouble, especially as the female grew older and went into heat.