If the USA had a basic public health system, people like Williams could receive the appropriate medical care. But, because a certain political faction wants to gut any program that might provide for care of those with mental disabilities, we should expect to continue to see many, many more cases like this.
There are those who say that we should just incarcerate them even if they do have a mental condition that obviously played a significant role in whatever occurred. Ironically enough, these are usually the same folks who complain about how much they pay in taxes. Well, incarcerating millions of people is very expensive and it has to be paid for by someone, so it winds up becoming our responsibility. A public health system would also have to be paid for by the public, but it's still cheaper than the costs of maintaining and creating even more prisons.
Unfortunately, that fact is lost on many Americans. We are a notoriously short-sighted society. We refuse to learn from anyone or any country or even our own past.
What happened to this baby could have been avoided if we had learned from the shooting of Gabrielle Giffords. Gifford's tragedy could have been avoided if we had learned something from John Hinckley Jr's attempted assassination of President Reagan. I could go on and on with cases that occurred between and before this one. We're fooling ourselves if we think that not funding public health care won't have devastating consequences for us all.
Contrary to the beliefs of many Americans, history give us a good idea of what to expect in the future. It shows that there will be plenty of tragedies like the one in this article. Until we stop treating these kinds of deaths as justified collateral damage in the (trumped-up) fight to maintain "American values", we are going to see many more folks lose their lives in one way or another.