I once watched a documentary on the first time the dangers of flying through volcanic ash clicked in and people were like "ohhhhhhh this is why..." so I found this pretty interesting. Don't know if anyone else will, but I'm going to share anyways (Buwahaha)

"LONDON - An ash cloud from Iceland's spewing volcano halted air traffic across a wide swathe of Europe on Thursday, grounding planes on a scale unseen since the 2001 terror attacks as authorities stopped all flights over Britain, Ireland and the Nordic countries.

Thousand of flights were canceled, stranding tens of thousands of passengers, and officials said it was not clear when it would be safe enough to fly again.

In a sobering comment, one scientist in Iceland said the ejection of volcanic ash — and therefore possible disruptions in air travel — could continue for days or even weeks..."