Why April?

That bombing at the finish line of the Boston Marathon yesterday is bothering me like it is most Americans.  The reasons are obvious.  But there is another thing that concerns me … why have so many of these actions happened in the month of April?

Some examples:

The Virginia Tech massacre:  April 16, 2007

Columbine high school mass murders:  April 20, 1999

Oklahoma City government office building bombing:  April 19, 1995

The end of a 50-day siege at a cult compound near Waco:  April 19, 1993

The assassination of Dr. Martin Luther King Jr:  April 4, 1968

And now a still-unexplained bombing of innocent people cheering on their loved ones at the end of a marathon, held each year on Patriot’s Day, a Boston holiday celebrating the beginning of the American Revolution.

Why April?