More than 6,400 migratory birds and other animals were killed in Nevada by drinking water in the cyanide-laced ponds produced by gold mining operations.
the poisoned water came from human mining that polluted water
( z1 come :ARG1 ( z2 water :ARG1-of ( z3 poison ) ) :ARG3 ( z4 mine :ARG0 ( z5 human ) :ARG0-of ( z6 pollute :ARG1 z2 ) ) )