HOUSTON — Donald J. Vidrine and Robert Kaluza were the two BP supervisors on board the Deepwater Horizon rig who made the last critical decisions before it exploded. David Rainey was a celebrated BP deepwater explorer who testified to members of Congress about how many barrels of oil were spewing daily in the offshore disaster.

Mr. Vidrine, 65, of Lafayette, La., and Mr. Kaluza, 62, of Henderson, Nev., were indicted on Thursday on manslaughter charges in the deaths of 11 fellow workers; Mr. Rainey, 58, of Houston, was accused of making false estimates and charged with obstruction of Congress. They are the faces of a renewed effort by the Justice Department to hold executives accountable for their actions. While their lawyers said the men were scapegoats, Attorney General Eric H. Holder Jr. said at a news conference, “I hope that this sends a clear message to those who would engage in this kind of reckless and wanton conduct.”

The defense lawyers were adamant that their clients would contest the charges, and prosecutors said that the federal investigations were continuing.

Legal scholars said that by charging individuals, the government was signaling a return to the practice of prosecuting officers and managers, and not just their companies, in industrial accidents, which was more common in the 1980s and 1990s.