I just wanted to speak about this because it upset me personally.
Patriot's Day in Massachusetts is a big deal. Obviously, there's the marathon, in addition to revolutionary war re-enactments at Lexington and Concord. I went to Boston University for undergrad and the marathon was quite possibly one of the best holidays of the year. Many people are off work/school and partake in the festivities of the day. People are lined up along the marathon route cheering the runners as they go by or grilling and drinking on rooftops of apartments overlooking the marathon. I've been a spectator around 5-6 times and I really hold this event close to my heart.
Fortunately for me, I'm pretty sure none of my friends that still reside there were injured or affected by the explosions. All I can say is that I hope the authorities working on this find whoever committed this act.
I've never run the marathon. I'd probably make it to mile 5 and call it quits. But for the determined few that train half a year for this event, and to reach the finish line when this catastrophe occurs... well, I can't describe how that would affect me. But for the runners that crossed the finish line and turned around to give aid in whatever way they could... there's no training for that. For all the bad in the world, there are those few that restore my faith in humankind. Honestly, I can't really say anymore that hasn't been said already. It's been rather surreal and I'm still having trouble convincing myself that this actually happened and wasn't just a bad dream.
Also, as a quick aside, please lay off the conspiracy theories, especially when there's absolutely no information available. There's always going to be coincidences, correlation does not imply causation, etc. etc. I really think you're doing more harm than good, and it's rather disrespectful to those that were affected by this tragedy.