Europe's volcanic ash response: was it adequate?

http://www.flightglobal.com/articles/2010/04/24/340995/europes-volcanic-ash-response-was-it-adequate.html


"When Iceland's Eyjafjallajökull volcano began erupting on 14 April, European aviation safety authorities were faced with an unprecedented dilemma and took drastic action: to avoid a loss-of-power disaster caused by engine damage, much of Europe's airspace was shut down the next day. Six days and $1.7 billion in airline losses later, flight bans were lifted.

But was the shutdown a massive overreaction or a necessary precaution?............"