I hate videos like this because it just ends with no conclusion.
Did the pit bull maul those children when it got on the bus? Did police show up and install some holes in it? Is the kid that got bitten recovering?
We don't know. All we can do is speculate.
In any case, any dog that can do that kind of damage should be allowed to go extinct naturally. Breeding them should be a federal crime or your state should have at least some serious laws preventing them from spreading. Having a pit bull in your home should be like having a puma or leopard. You should have a special license and be certified to keep one in your home.