Crewmembers of a Coast Guard helicopter based in Kodiak received an emotional welcome last night when they returned home after their HH-60 crashed during a dangerous rescue operation Wednesday night.

Crewmembers of a second Coast Guard helicopter who plucked their colleagues from the Bering Sea off Unalaska Island shared in the welcome at the Kodiak Air Station hangar, where more than 100 family members and fellow Guardsmen gathered. Meanwhile, the Coast Guard continued the search past nightfall for six crewmembers from the freighter Selendang Ayu who were aboard the downed helicopter.

The crew of the helicopter from the cutter Alex Haley that rushed to deploy and rescue their fellow Coast Guardsmen arrived on a C-130 just before 6 p.m., still wearing their bright orange jumpsuits.

Then a C-12 aircraft touched down at about 7:30 p.m. with the crew of the HH-60 that crashed, including the three Coast Guardsmen who were rescued: Lt. Dave Neel, Lt. Doug Watson and Petty Officer Brian Lickfield.

With them was rescue swimmer Aaron Bean, who stayed with the captain of the Selendang Ayu as the grounded ship broke in half.

Bean and the captain were taken off the freighter after the helicopter crew and one other crewmember from the Selendang Ayu were rescued.

Family members rushed across the hanger as their husbands and fathers entered. Coast Guardsmen waited a step behind with handshakes and pats on the back to welcome their comrades.

The three rescued crewmembers were given medical attention in Dutch Harbor and had no major injuries, but the exhaustion of the last day still showed on their faces.

Television, radio and print media were all present to cover the homecoming. The media was instructed that interviews with the rescued crewmembers would be inappropriate with the investigation into the crash still under way.

Still, Coast Guardsmen grouped around rescued helicopter crew member Lt. Neel who briefly recounted details in an emotion-laden account of the crash and rescue as families and well-wishers mingled.

Rear Adm. James Olsen accompanied the rescued Coast Guardsmen and read a letter sent to him by Gov. Frank Murkowski thanking the crews for their bravery.

“On behalf of all Alaskans, I would like to extend to the Coast Guard our sincere gratitude for the heroic response by your command to the unfortunate and tragic grounding of the freighter Selendang Ayu,” the letter stated.

“Our prayers are with the crew of the freighter and with the Coast Guard personnel whose unflinching bravery in the face of terrible weather and high seas put them in harm’s way.”

A major spill of dense, viscous fuel from the freighter that ran aground was menacing sensitive wildlife habitat in the Aleutian Islands today, but finding the six crewmembers lost at sea remained a priority — despite their diminishing odds for survival.

Thousands of gallons of heavy bunker fuel and diesel spilled from a soybean freighter that was ripped clean in half off the shore of Unalaska Island. Near a wildlife refuge, the area is home to sea lions, harbor seals, sea otters, tanner crabs, halibut and kelp beds.

But with resources scarce in the remote and harsh area 800 miles southwest of Anchorage, the search for the missing took precedence over the environmental threat.

‘‘There are only so many boats and so many planes, and they have been directed to the search for life,’’ Kurt Fredriksson, acting commissioner for the Department of Environmental Conservation, said Thursday.

Coast Guard rescue crews searched into the night, with officials saying they had not given up on finding someone alive. Estimates put survival in the 43-degree waters of the Bering Sea at about three hours.

No sign of the missing crew had been found as of this morning, a coast guard spokeswoman said. Petty Officer Amy Thomas said there were no aircraft searching in the dark, but they would fly out at first light late morning.

Thomas said two cutters were at the scene of the grounding and another cutter with oil vacuuming equipment was en route from the Prince William Sound town of Cordova, about 930 air miles to the northeast. The vessel is expected to arrive tonight or Saturday morning, Thomas said.

The six crewmembers were plunged into the sea when a Coast Guard helicopter crashed at about 6:15 p.m. Wednesday while evacuating them from the freighter. Four others, including three Coast Guard personnel, were rescued from the water by a second helicopter from the cutter Alex Haley that evening and were in good condition Thursday.

The Coast Guard said the cause of the crash was still unknown.

The 738-foot Selendang Ayu was cleaved neatly in two, both pieces grounded upright and parallel about 200 feet from the shore near Skan Bay on the western side of the island. Farther upshore lay the wreckage of the Coast Guard helicopter, its red fuselage blackened and barely recognizable.

The freighter belongs to Singapore-based IMC Group. IMC crew manager Loh C.W. Weng said the missing were Indian citizens Z.M. Vaz, age 46; Blaise M. Mascarenhas, 33; Narendra S. Yadav, 52; Durg V. Singh, 54; and Didlar Singh, 44. Carlos Flores Santiago, 45, is the missing crew member from the Philippines.

Rescuers battled rolling seas, 30-knot winds and the thin Alaska daylight. On Thursday evening, officials said boats would continue the search into the night.

‘‘It’s always challenging in the Alaska environment, but these aircraft crews are some of the best we’ve got,’’ Coast Guard Chief Petty Officer Darrell Wilson said.

Fredriksson said it was not known how much fuel had leaked, but called it a major spill that could take months to clean up, threatening sensitive wildlife habitats.

‘‘You’ve got bunker oil streaming from a ship that’s broken in half,’’ he said. ‘‘We are in winter and in a very difficult Aleutian Island environment that will put everybody to the test.’’

The freighter was carrying 480,000 gallons of heavy bulk fuel and another 21,000 gallons of diesel fuel.

IMC has contracted a private spill response company, Fredriksson said. He said the rough seas could help break up some of the oil and disperse it to the open sea. ‘‘That may be a good thing, in terms of shoreline impact,’’ he said.

DEC spokeswoman Lynda Giguere said conservation officials will be working with the Department of Fish and Game to determine potential threats to wildlife.

‘‘The fuel we’re dealing with is No. 6 fuel oil. It’s a very dense, viscous oil and it’s not easy to clean up,’’ Giguere said. ‘‘This is particularly persistent. It’s high viscosity and it tends to remain on the surface. It’s not good stuff.’’