As rescuers anxiously waited for dawn to break to continue searching for the six Thursday, the Coast Guard was responding to a possible fuel spill near a sensitive wildlife habitat.
Four others on the helicopter - three Coast Guard personnel and one crew member - were picked up by another helicopter participating in the rescue, the Coast Guard said. They were taken to Dutch Harbor on nearby Unalaska Island for medical treatment.
Coast Guard officials said the crew member was treated for a neck injury. No injuries among the Coast Guard personnel were reported.
Two other people who had stayed on the ship were rescued separately, as were 18 other crew members taken off the ship earlier.
The Coast Guard had been struggling to help the 738-foot freighter, the Selendang Ayu, since Tuesday when it began drifting after its main engine broke down. But 25-foot swells and 30-knot winds hampered their effort.
The freighter, which was carrying grain, is owned by Singapore-based IMC Group and is registered under a Malaysian flag. Its crew was Filipino and Indian, the Coast Guard said.
Coast Guard Chief Petty Officer Roger Wetherell said a plane and two helicopters would be dispatched after daybreak Thursday to join the search for the six missing. The water temperature was about 43 degrees and the waves were as high as 20 feet.
``The survival time is right around three hours in those conditions,'' Rear Adm. James Olson, commander of the Coast Guard in Alaska, said earlier. ``We'll search as long as we can be effective throughout the night.''
Olson said he did not know whether the crew members were wearing survival gear. The cause of the crash was not immediately known.
Meanwhile, officials were trying to determine how much fuel spilled into the water when the freighter went aground and split apart on a remote shore of Unalaska Island in the Aleutian chain.
The carrier's 440,000 gallons of heavy bunker oil had been transferred to inboard tanks and the fuel heaters were turned off to thicken the fuel, so it would not disperse if it spilled, Petty Officer Thomas McKenzie said.
A tug boat had attached a line to the freighter on Tuesday evening, securing it for 12 hours. But then the line broke and the vessel resumed its path to the Unalaska Island shore.
The crew of the Selendang Ayu dropped anchor when it reached shallow water, but it was lost in the rough seas after just a half hour.
The crew later dropped its other anchor, which for a while held the freighter four-fifths of a mile from shore, Olson said.
Sometime around 6 p.m. Wednesday, the captain of the freighter requested the remaining crew member be evacuated from the vessel, as the anchor had begun to give way and the freighter had started to flood.
Eight were on board, after 18 had been previously evacuated.
The helicopter crashed into the sea soon after picking up crew members, leaving behind the captain and a Coast Guard rescue swimmer. They were later rescued by the second helicopter. Around 7:15 p.m., the freighter broke in half.
The Selendang Ayu is a single-deck bulk carrier built in China in 1998. It is owned by IMC Transworld, a subsidiary of IMC Group.
Company representatives are in Dutch Harbor and have met with Coast Guard officials, Olson said.
Olson said all Coast Guard personnel had been accounted for.
