A woman makes a phone call in the empty arrival hall of Prague's Ruzyne Airport after all flights were grounded due to volcanic ash in the skies coming from Iceland April 18, 2010. Air travel across much of Europe was paralyzed for a fourth day on Sunday by a huge cloud of volcanic ash, but Dutch and German test flights carried out without apparent damage seemed to offer hope of respite. (REUTERS/David W Cerny) #
Lava and lightning light the crater of Eyjafjallajokul volcano on April 17, 2010. (REUTERS/Lucas Jackson) #
