Toxic sludge flood
Hungarian firefighters clean a yard flooded by toxic mud in Devecser, Hungary, on Oct. 6.
The flooding was caused by the rupture of a red sludge reservoir at an alumina plant in western Hungary on Monday and has affected seven towns near Ajkai, 100 miles southwest of Budapest.
The flood of toxic mud has killed at least four people and injured more than 100. Some people are missing.