Who Should Pay For The Volcano?

So a massive volcanic eruption closes Europe’s airspace for several days, costing the airline industry somewhere in the neighborhood of $2 billion dollars. Individual travelers have also suffered various costs, including hotel stays, meals, lost business or income, and even additional airport parking fees. Given the size and scope of such impacts of a natural disaster, who should be responsible for these costs?

Links:
Who should pay for the volcano disruptions? (BBC Blogs)
Ash chaos, anger over cost grows (BBC)
Air travel disruption after 2010 eruption (Wikipedia)