Updated

A Somali man was sentenced to life in prison on Monday for his role in the hijacking of yacht off the coast of Africa that left all four Americans on board dead, telling a federal judge that he never meant for anyone to get hurt.

"I'd like to express my regret and sorrow to the victims' families," Ali Abdi Mohamed said through an interpreter.

Mohamed is the first of 11 men who have pleaded guilty to piracy in the case to be sentenced. Each of the men face mandatory life sentences, although that could eventually be reduced as part of a plea deal with federal prosecutors. A second Somali was expected to be sentenced later in the day.

The owners of the Quest, Jean and Scott Adam of Marina del Rey, Calif., along with friends Bob Riggle and Phyllis Macay of Seattle, were shot to death in February several days after being taken hostage several hundred miles south of Oman. They were the first Americans to be killed in a wave of piracy that has plagued the Indian Ocean in recent years.

The pirates said they intended to bring the Americans back to Somalia so that they could be ransomed, but that plan fell apart when four U.S. Navy warships began shadowing them. The Navy offered to let the pirates take the yacht in exchange for the hostages, but the pirates said they wouldn't get the kind of money they wanted for it. Hostages are typically ransomed for millions of dollars.

Mohamed told prosecutors he was ordered to fire a rocket propelled grenade at the American warships to keep them away from the Quest. Court documents say that in doing so, he inadvertently killed one of the pirates who was standing too close behind him. Shortly after the RPG was fired, gun fire erupted aboard the yacht.

Court records say three of the men shot at the Americans and that stray bullets they had fired killed another pirate. Mohamed said he another pirate rushed downstairs to where the Americans were being held to wrestle the weapons of the shooters away and to get them to stop shooting, but it was too late.

Mohamed said that even though he didn't shoot the Americans, he hopes their families will forgive him. None of the victims' family members were present Monday, but they sent in numerous letters saying that their loss has been devastating. District Judge Mark Davis said that by all accounts, the victims lived lives filled with "service and with kindness to those they encountered."

The Adams had spent much of their time delivering Bibles around the world.

Three men are charged with murder and other death-penalty eligible charges. A fourth man also faces piracy charges for acting as a land-based negotiator for the band of pirates.

Mohamed and the others have agreed to help prosecutors in those cases and possibly others.

In all, 19 men boarded the Quest. When American forces boarded the boat, all but two men surrendered. Those two were shot and killed by U.S. forces.

U.S. authorities released one person because he was believed to have been a juvenile.

The prison Mohamed and the others will be sent to hasn't been determined.