NEW ORLEANS (AP) -- Prosecutors tried Tuesday to persuade a federal appeals court to reinstate some of the manslaughter charges against two BP employees in a case arising from the deaths of 11 workers in the 2010 Deepwater Horizon rig explosion in the Gulf of Mexico.
BP well site leaders Robert Kaluza and Donald Vidrine were indicted on 22 manslaughter counts in connection with the 11 deaths. Prosecutors said they failed to act on pressure readings that provided "glaring indications" of trouble ahead of the disaster. Both have pleaded not guilty.
U.S. District Judge Stanwood Duval Jr. last year threw out 11 counts of "seaman's manslaughter" against the two. He said the charges exceeded the intended scope of the statute in connection with the job duties of the two men. Eleven counts of involuntary manslaughter remain.
Federal prosecutors appealed Duval's decision to the 5th U.S. Circuit Court of Appeals, where a three-judge panel heard arguments Tuesday. There was no indication when the judges — Patrick Higginbotham, Edith Jones and Edward Prado — would rule.
Prosecutors argue that Kaluza and Vidrine botched a key safety test and disregarded high pressure readings that were signs of trouble before the blowout of BP's Macondo well.
However, the issue before the appeals court is not what happened on the Deepwater Horizon but whether a section of federal law referred to as the "seaman's manslaughter" law applies to Kaluza and Vidrine — or to anyone on the rig.
The defense says the law covers vessels attached to and erected on the Outer Continental Shelf. Kaluza's and Vidrine's lawyers note that the Deepwater Horizon was a portable rig that floated on pontoons, kept in place solely by its own engines.
Prosecutors argue that law clearly applies to drilling vessels and other watercraft when they are connected to the seabed through drilling mechanisms.
Even if the law does apply to the rig, defense lawyers argue, it does not apply to their clients.
The law applies to neither Kaluza nor Vidrine because neither was a captain, engineer, or pilot of the Deepwater Horizon, defense lawyers argue. "Nor were they members of the marine crew that was responsible for the operations, maintenance, or navigation of the vessel; rather, they worked with the rig's drilling crew."
Prosecutors say the language of the law does cover the two.
"Congress, recognizing the special dangers associated with activities on the water, used the unambiguous phrase "or other person employed on ... any vessel" to demand increased vigilance from the entire class of persons who, through their employment on a vessel, hold in their hands the safety and well-being of those on board," says one Justice Department brief being considered by the three judges.
The seaman's manslaughter charges carry possible fines, prison sentences of up to 10 years, or both. The involuntary manslaughter charges carry possible fines, prison sentences of up to eight years or both.
In addition to causing the deaths of the workers, the April 20, 2010, explosion spawned the nation's worst offshore oil spill.