More than 2,000 family, friends and sympathizers gathered inside the Coast Guard Air Station Barbers Point hangar yesterday to pay tribute to four Coast Guard HH-65 Dolphin helicopter crew members who were killed after their aircraft went down for reasons unknown on Sept. 4.

The crash occurred about 5 miles south of Honolulu International Airport during an evening rescue exercise with a Honolulu Station lifeboat.

Speaking at the 90-minute memorial, Adm. Thad Allen, commandant of the Coast Guard, said the loss of the men was devastating to their families, as well as to the Coast Guard "family" as a whole.

Following the service, Allen described the four killed as among the most experienced air crews in the entire Coast Guard.

"The purpose today was to cherish the lives of these individuals, understand what they did for this country, understand what they meant to the Coast Guard — but moreover, what they meant to their families," said Allen, who flew in from Washington, D.C., for the occasion.

"As I told each one of the individual families, these are all very difficult times and difficult journeys. My message to them was you are not making it alone."

Along with Allen, there were remarks by the air station's commanding officer, Capt. Brad Bean, and Master Chief Petty Officer Skip Bowen, the service's senior enlisted member.

"On the night of Sept. 4, the crew of the Coast Guard 6505 was on a routine training flight," Bean told those present. "There was nothing unusually risky about this flight, but last Thursday night, something heartbreaking happened that resulted in the loss of our friends."

The formal ceremony included a Coast Guard ceremonial color guard, the National Anthem performed by the Coast Guard Band, a rifle salute, and taps.

The ceremony climaxed with a flyby of two HH-65 Dolphin helicopters moving in a three-helicopter formation — the missing aircraft representing the Dolphin that went down during the training exercise.

One of the Dolphins then broke away and continued out to sea where its crew placed a wreath on the waters where the crash had occurred.

Three of the four crew members killed that evening were found outside the partially submerged helicopter. They were co-pilot Lt. Cmdr. Andrew Wischmeier, 44, of Fort Lauderdale, Fla.; rescue swimmer Petty Officer 1st Class David Skimin, 38, of San Bernardino, Calif.; and flight mechanic Petty Officer 2nd Class Joshua Nichols, 27, of Gloucester, Va.

A massive air and sea search — covering 2,500 square miles and involving federal, state and county agencies — was launched to recover the missing pilot, Cmdr. Thomas Nelson, 42, of Staten Island, N.Y. The round-the-clock hunt was called off after three days.

Allen lamented that Nelson's body was not recovered, and said the tragedy was especially difficult to reconcile considering the crash occurred during a rescue exercise.

"You don't expect things like this to happen on a routine training flight," he said. "But we do not work in a risk-free environment. And we're coming to grips with the fact that it's hard to explain when a crew that good was lost apparently unnecessarily."

Although officials have said little about what may have caused the crash, spokesman Lt. John Titchen said two Coast Guard investigation teams are conducting exhaustive probes, and the results will be made public when the inquiries are concluded.

Coast Guard officials reportedly got a distress signal from the 47-foot vessel participating in the exercise prior to the crash at 8:15 p.m. It was also reported that there had been problems with a line that lowered a rescue basket from the Dolphin to the lifeboat.

Titchen said Coast Guard crews from three Mainland air stations and three small boat stations have been brought in to conduct the exercises while the investigation is in progress.

"We are standing down local crews from that particular exercise while they are evaluated," said Titchen, who added that the Mainland crews would remain for about a week, or as long as necessary until the local crews are deemed ready.

Titchen said the investigations could last from a few weeks to several months.