Pedestrians walk in through fog on the Aristotelous square promenade in the northern Greek city of Thessaloniki on Monday, Feb. 17, 2014. Dense fog has settled over the city, leading to some plane ... more 
Pedestrians walk in through fog on the Aristotelous square promenade in the northern Greek city of Thessaloniki on Monday, Feb. 17, 2014. Dense fog has settled over the city, leading to some plane flights being re-routed and take-off delays. (AP Photo/Nikolas Giakoumidis) less 
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Associated Press | Photo By Nikolas Giakoumidis
Mon, Feb 17, 2014 9:54 AM EST