Grimsvotn Eruption

In a case of internationally joined efforts to reduce risk in line with the behavioral paradigm, flights were shut down in May this year over a 120-square mile area in Iceland.  This was a necessary step, as much of that area was obscured by a pillar of ash and debris kicked up by the Grimsvotn eruption.  370 flights were canceled, and rightfully so.

((Article at: http://www.huffingtonpost.com/2011/05/21/grimsvotn-eruption-2011-iceland-volcano_n_865150.html#s282574&title=Iceland_Volcano_Eruption))