Boston Strong?

What are the criteria that have to be met before an event can be officially defined as a tragedy? Is it the scope of the event, or is it more about the people affected? Is a school shooting more of a tragedy than an office massacre because the victims might be primarily children?
 I have no idea, but what I do know is a tragedy is an event, and an event has to happen within a space.  It is very likely these spaces will be in a major city in the past this has presented abundant opportunities for profit.
 After 9/11 everyone wanted to by New York themed merchandise, after the Boston Marathon bombing a popular hashtag was adopted for a hot selling piece of merchandise a simple bracelet that said "Boston Strong" on it. So tragedy presents an opportunity for financial gain sure, but the problem is there is no way of knowing where and when one might happen. This might leave a potential producer of tragic accessories at a marked disadvantage. So what do you do? After 9/11, a lot of merchandises was produced based on specific references to the attack. One example is the t-shirt that featured the twin towers with accompanying text that said something like "9/11 never forget" The events of Boston changed this though. Instead of depicting anything specific from the event it was decided simply to adopt a slogan "Boston Strong" This is probably because unlike 9/11 there wasn't much iconic imagery that lent itself to an image that could be printed on a t-shirt. Now that it's possible to be this vague it is also possible to being producing merchandise that will be ready to go the minute the next "national tragedy" occurs in a major American city. Two words are all that's needed the name of the city and some positive sounding adjective. I'd recommend making a few different ones for each city, try out each hashtag and see which is most commonly used and there you go that will be the one you sell. People can feel like they've come together and stood against soe vague evil after they've paid five bucks for something that reads #chicagoreal or #LAtough or #cleavlandcool