It was standing room only in the simple, white clapboard Anglican cathedral here as residents came this afternoon to pay tribute to the 248 U.S. troops of the 101st Airborne Division killed in a fiery airplane crash on the edge of town Thursday.

The ecumenical memorial service noted the irony that American soldiers on the last leg of a journey home from peace-keeping duty in the tumultuous Middle East would die on friendly soil so near Christmas.

"All of these things together add up to a situation and circumstance that is difficult for us to encompass and difficult to understand and difficult for us to express the way we feel," said U.S. Ambassador Thomas Niles, who bowed to the American flag draped by the rector on the altar and spoke in a hoarse voice, choked with emotion.

Violent death is well known to this storm-swept Canadian island in the North Atlantic. Natives call it "The Rock," both because of its stony landscape and the hardy souls who brave the severe elements.

In the last two decades, more than 100 persons have died in six separate air crashes on the island. In 1982, 84 laborers died when the Ocean Ranger oil rig collapsed offshore. Numerous deaths have occurred in blizzards and other storms.

"We are a seafaring people, and tragedy by sea is not uncommon," said white-haired James Strong, 73, a retired telecommunications manager at the airport. He was among more than 500 in the cathedral waiting for the services to begin.

"You don't talk about past tragedies," he said. "You remember them with a deep sense of, I suppose, faith."

The Rev. Ed Bromley of St. Joseph's Roman Catholic Church, where about 500 others from the town of 12,000 watched the services on closed-circuit television, spoke in his homily of the "fragility of our day-to-day existence."

"Let us mourn with those who mourn," he said. "Let us also mourn with those whose faith is shattered and who at this time see only a savage God. Let us tell them that we understand and that we will walk with them in their dark night."

The reason why the chartered Arrow Air plane crashed on takeoff after a refueling stop here remained a mystery.

At a press conference and later in a private briefing for Niles and Canadian Attorney General John S. Crosbie, the chief investigator of the crash, Peter Boag, said the probers so far had no clues.

Boag, of the Canadian Aviation Safety Board, expressed guarded optimism that analysis of the DC8's battered flight-data recorder might provide important information regarding airspeed, altitude and rate of the aircraft before it fell a half mile south of the runway and exploded into flames on a forested slope.

Boag said his team here, which is being aided by U.S. aviation experts, was waiting for numerous records on the Miami-based Arrow Air Inc., including reports that the same plane had aborted on takeoff from Grand Rapids, Mich., last month.

In his session with Niles and Crosbie, according to the American ambassador, Boag tended to discount speculation that the pilot's failure to have the plane de-iced before it took off in light snowfall might have added weight to bring down the jetliner.

"It's a very difficult investigation because there were no survivors and because of the catastrophic destruction of the aircraft," Boag said, "but I'm optimistic the cause of this crash will be determined by the board."

At the aircraft hangar that is the morgue for the 101st troops and eight Arrow Air crew members, U.S. Army morticians, grave registration specialists and others prepared for the departure Monday of the first 20 flag-draped metal coffins to the Dover, Del., Air Force base in two C141 military transport planes.

Autopsies and identifications are to be completed there. The rest are to be flown out Tuesday and Wednesday.

One of the C141s sat idle on the runway with mechanical problems this morning as the U.S. military team waited for parts so the plane could be repaired in time for the planned departure Monday afternoon.

An honor guard from the 101st Airborne home base at Fort Campbell, Ky., is to arrive Monday to escort the caskets back to the United States. Maj. Gen. John S. Crosby, the head of the Pentagon contingent, said the ceremonies "will be very similar to those when our marines came back from Beirut."

An American flag flew at half staff outside St. Martin's cathedral as Royal Canadian Mounted Police in gold and scarlet coats, beribboned Canadian legionnaires and U.S. airmen and soldiers in green fatigues sang with the townspeople "The Lord Is My Shepherd" and "The Battle Hymn of the Republic." A Salvation Army bugler blew a mournful "Retreat."

For the residents of this town, whose major source of livelihood is the airport, the disaster has prompted a mixture of emotions.

The flood of press with their cameras, lights and chartered planes had caused some excitement.

Newfoundland is Canada's poorest province, with unemployment at just under 20 percent now. The island is heavily dependent on fishing, but fish have been scarce and competition from international fishermen intense this season. The government devised work projects so fishermen could work long enough to be eligible for unemployment compensation.

The press influx has increased sales of local merchants, with long underwear a hot item. Taxi drivers who get $2 to carry customers from the airport to the downtown hotels have been signed on by television networks for $200 a day.

Clara Byrne said people talk a lot about fate when discussing the busy refueling stop here for North Atlantic flights.

Some townspeople observed that had the pilot of the DC8 used the other runway, and had the same problems developed, the plane could have exploded right in the middle of town.

But Byrne said she does not allow herself such worries. "You live with the odds," she said, "and the odds are against it."

The Associated Press, meanwhile, reported:

ABC News played a tape recording from one of the Gander crash victims, Spec. 4 Jeff S. Kee of Pensacola, Fla., in which he complained about the aircraft to his fiancee, Tracy Walker of Hopkinsville, Ky.

"I just hope," Kee said in a tape he sent Walker from Egypt, ". . . the plane gets back all right 'cause . . . the plane we fly on is really bad."

Walker told ABC News that Kee had told her that "he knew he would make it through for six months over there but when he came back, he didn't know, that he would, you know, exactly make it because the planes were in such bad shape."

June Duckworth of Westport, Mo., the mother of 28-year-old Staff Sgt. James Duckworth, who died in the crash, said the government killed her son by flying him home for the holidays in a plane that was a "bunch of junk." She said she would not attend a military memorial service.