"A man's handgun went off while he was holding it..."
From an AP news story - not sure who wrote it, but that statement is all kinds of wrong. The gun didn't just "go off". He failed to keep his freaking finger off the trigger.
In fact he breached each of the four rules in sequence as if running a checklist to ensure catastrophic failure.
He will live in his own personal Hell for the rest of his days after shooting his own 7 year old son.
7 years old. The word "tragic" just isn't sufficient.