NEW ORLEANS – Federal authorities have blamed two rig supervisors for the deaths of 11 workers killed when the Deepwater Horizon exploded and spawned BP’s massive oil spill in the Gulf of Mexico, even though a string of investigations spread fault among a host of people and companies.

A federal indictment last week charged Robert Kaluza and Donald Vidrine with manslaughter, accusing them of botching a crucial safety test. But a defense attorney claims the two BP well site leaders are scapegoats, given that other government probes have concluded the disaster resulted from a complex web of mistakes and a corporate culture that placed profits ahead of safety.

One expert speculated the Justice Department probably took aim at targets higher up BP’s corporate ladder before charging Kaluza and Vidrine.