Some details of the U.S. forces' deadliest day so far in the war in Afghanistan remain unclear, Pentagon officials said Wednesday, including whether a Navy SEAL was captured and murdered by Al Qaeda.

"We may never know," said Secretary of Defense Donald H. Rumsfeld.

Rumsfeld and the war's commander, Gen. Tommy Franks, were responding to reporters' questions about what they knew about the death of Petty Officer 1st Class Neil Roberts of Woodland, Calif. He and six other Americans were killed Monday after U.S. helicopters assaulting Al Qaeda and Taliban fighters were hit by enemy fire in eastern Afghanistan.

Asked about reports from a field commander that Roberts had been dragged away by Al Qaeda and shot dead, Franks said he wasn't sure.

"I think there are a variety of possibilities of the way" Roberts may have died, he said.

Roberts fell to the ground as his stricken chopper, hit by a rocket-propelled grenade, veered up and away toward safer ground, officials said.

Commanders watched as an unmanned Predator surveillance aircraft relayed live video of Roberts being taken away by Al Qaeda members, said Maj. Gen. Frank Hagenbeck, commander of the operation to encircle and kill enemy fighters.

"We saw him on the Predator being dragged off by three Al Qaeda men," said Hagenbeck.

Roberts apparently survived the fall and was shot on the ground, said Marine Maj. Ralph Mills, speaking for the U.S. Central Command in Tampa, Fla.

Whether he was taken away to be killed, was already dead when taken away or wounded when taken and died later remains unclear, Franks said Wednesday.

"There will be a lot of views on this particular incident," Franks said. "I have talked to three, maybe four people, who were either present or have reviewed the result of this, and it would probably not surprise you that each of the three or four has a different view of what happened."

He cautioned that first and second reports can often prove wrong.

"I'm not sure yet," he said. "And I think, as we work our way through this, we will come to some greater clarity."

Rumsfeld said details are not the point.

"We know a fine American is dead," he said. "It is not whether the bullet hit him from ground fire while he was still in the helicopter or after he fell to the ground ... or after someone came up and shot him again. We may never know that."

The existence of the Predator pictures was revealed by Hagenbeck in Afghanistan and not by Pentagon officials as they described the incident in briefings Monday and Tuesday.

Rumsfeld was asked if officials held back word of the video because they didn't want Americans reminded of the 18 casualties from the 1993 incident in which helicopters were downed in Somalia. Television footage showed Americans back home that the body of one of the victims was dragged through the streets of the capital, Mogadishu.

"Other than very brave people being involved, this has nothing to do with Mogadishu," he answered. "And the individual who was killed, his body has been retrieved, and so too have the wounded. And I don't see any comparison."