Hopefully this scenario doesn't happen, but I'm assuming there is an alternative route in the event that Etna acts up?
http://www.upi.com/Top_News/World-News/2011/04/11/Mount-Etna-volcano-calms-down/UPI-35571302531440/
http://www.upi.com/Top_News/World-News/2011/04/11/Mount-Etna-volcano-calms-down/UPI-35571302531440/