I think what you fail to realize is that the tragedies have not changed, the media and delivery of news has. In this day and age we get minute by minute live feed of events right when they occur. This gives the entire public a chance to jump into the speculation as the FBI, CIA, etc. try to figure it out. This is where conspiracy theorists come in. It's in everyone's drive as a community to find justice and right any wrongs, even if that means finding wrongs in the government.
There have been tragedies identical to this for over one hundred years.
This is a prime example. A guy got pissed about higher taxes and bombed an elementary school because that school raised property taxes. Things like this happen on an entirely domestic level, often as a retaliation against government. The nature of the bombs in Boston yesterday lead me to believe that it's homegrown terrorism against something related to Boston or the marathon or the state of Massachusetts. But it's so early in the investigation I'm not guessing anything more than that because nobody knows anything.
Honestly you're kind of reminding me of Dale Gribble from King of the Hill right now.