Volunteers pass sand bags from hand to hand to place them at an entrance of the former chemical plant 'Zorka'  in the city of Sabac, 100 kilometers west of Belgrade, on May 18, 2014. Thousands of people crammed into boats and army trucks fled their homes in Serbia and Bosnia today after record rainfall turned the Sava river into a deadly torrent and caused the worst floods in more than a century. According to officials in both countries, the disaster has killed at least 44 people.  AFP PHOTO / ANDREJ ISAKOVIC        (Photo credit should read ANDREJ ISAKOVIC/AFP/Getty Images)