Indeed it is sad and would drive any sane man and woman insane that we in America are not able to protect our children and citizens from the guns that are being abused by the crazies and the terrorists.
The cause of this tragedy, I believe, goes right back to the beginning of this great country, necessity and love for guns by the forefathers and the subsequent constitutional protection, the second amendment, the right to arm oneself.
As a physician, I know only too well the limitations of a human being in all different aspects, in handling guns under all different circumstances. I believe that is why we see and hear so often even the trained policemen shooting unarmed innocent black youths.
A good friend of mine, a surgeon(a Chinese) used to tell me I should keep a gun at home.
He had a gun in his safe at home. One day his son, who was suspended for one week at his high school by being caught smoking,
was so afraid of his father who would be mad at him and decided to commit suicide with his father's gun and shot his one side of
his head. To make a long story short fortunately he survived and grew up to be a normal adult after enduring some twelve brain surgeries at Mayo Clinic. What his family went through can be made a remarkable story book.

There are several versions of the text of the Second Amendment, each with capitalization or punctuation differences. Differences exist between the drafted and ratified copies, the signed copies on display, and various published transcriptions.The importance (or lack thereof) of these differences has been the source of debate regarding the meaning and interpretation of the amendment, particularly regarding the importance of the prefatory clause.

One version was passed by the Congress.

As passed by the Congress and preserved in the National Archives, with the rest of the original hand-written copy of the Bill of Rights
prepared by scribe William Lambert:

A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.

As ratified by the States and authenticated by Thomas Jefferson, then-Secretary of State:

A well regulated militia being necessary to the security of a free state, the right of the people to keep and bear arms shall not be infringed.(From Internet)

U.S. Is the only civilized country that allows an ordinary citizen can carry a gun in the world. 90% of Americans agree with background check when guns are purchased. I live in redneck town. Almost everyone has gun(s) and believes that carrying are gun will protect one from gun violence. It won't be easy to achieve a reasonable gun control in USA.