They have been melted down, or have been smashed together. They were not able to save the one who carried them, and their life will go into captivity
Other versions
King James Version
They stoop, they bow down together; they could not deliver the burden, but themselves are gone into captivity. English Standard Version
They stoop; they bow down together; they cannot save the burden, but themselves go into captivity.New International Version
They stoop and bow down together; unable to rescue the burden, they themselves go off into captivity.