UPDATE: The CBC is reporting that the Ontario couple killed in last Thursday's helicopter crash have been identified as Stuart Robertson and Birgitta Wannersjo.
Both worked in Toronto, for a defence and aerospace company. On Monday night, colleagues expressed devastation at the news.
"We're going to miss them ... They had been here for several years and both of them were well liked by their colleagues and turned in good efforts while they were here. We'll miss them a lot," former co-worker Mike Waterstat, said.
The accident claimed five lives.
HONOLULU, Hawaii - A National Transportation Board Safety investigator arrived in Hawaii Friday to begin probing why a tour helicopter slammed into a ridge on Molokai island, killing two Ontario tourists and three others on board.
The investigation will begin immediately, said Federal Aviation Administration spokesman Allen Kenitzer. A preliminary report typically would come within a week or two, but it could be months before the probable cause of the crash is determined.
The Blue Hawaiian Helicopters flight was on a 45-minute aerial tour of west Maui and Molokai when it crashed around midday Thursday.
The Eurocopter EC-130 was engulfed in flames after crashing about a quarter-mile from an elementary school. School officials saw the helicopter hit the hillside above campus and heard a loud boom.
Firefighters recovered four bodies and the fifth was located under the wreckage, Maui County spokesman Rod Antone said.
Pennsylvania newlyweds Nicole and Michael Abel, and a man and a woman from Ontario were killed in the crash.
The relationship between the Ontario tourists hasn't been confirmed, Antone said.
The pilot, 30-year-old Nathan Cline, was also killed in the crash, Maui County officials said.
The Department of Foreign Affairs and International Trade said Friday it was aware of reports of Canadian citizens being involved in a helicopter crash in Hawaii.
"Our sympathies are with the family and friends of the victims," spokeswoman Claude Rochon said in an email.
"The Canadian consulate in San Francisco has been notified and along with our Australian counterparts in Honolulu, stand ready to provide consular assistance as required."
The U.S. couple killed in the crash were both young nuclear engineers from the Pittsburgh area who had married recently, said Westinghouse Electric Co. spokesman Vaughn Gilbert.
"Clearly this is a tragic loss for the families involved and for Westinghouse. They had so many friends and colleagues who speak glowingly of them," he said.
"They had their whole careers, their whole futures ahead of them. It's a tragedy."
Blue Hawaiian Helicopters owner David Chevalier also expressed his sympathies for the families of the victims Friday.
"We're extremely grieved for our pilot as well as the passengers," he said. "Something like this can't be more devastating to us."
Condolences for the pilot poured in on Blue Hawaiian's Facebook page Friday evening.
"Nathan had a wonderfully quirky sense of humour, gave a memorable tour of the islands, and was an all-around great guy," wrote Rafael Perrino, who flew with Cline on the West Maui-Molokai tour in August. "My heart goes out to Nathan's family, the families of lost passengers, and the Blue Hawaiian Helicopters team."
Kristin Zukis Gray said she was on the same tour two months ago and called Cline "a great, sweet, nice kid."
"May he rest in peace. And take solace in the fact that he died doing something that he truly loved — you could tell the second you stepped on board and put on your headphones how much he enjoyed what he did," she wrote.
The chopper that crashed was less than a year old and was being leased from Nevada Helicopter Leasing LLC, Chevalier said.
Neither Maui police or Blue Hawaiian Helicopters returned phone calls seeking comment Friday.
The Maui Visitors Bureau was helping families of the victims, and the Maui Police Department's chaplain was on site, county officials said.
The crash occurred about a half kilometre from Kilohana Elementary School, prompting teachers to keep the 71 students inside, Principal Richard Stevens said.
"We didn't go on lockdown," he said. "The kids were never in any immediate danger."
Stevens said a school health aide saw the helicopter hit the hillside in the mountains above the campus, and there was a large boom.
"We just had a heavy downpour," Stevens said. "You could see smoke coming up, even though it was very cloudy."
The helicopter was engulfed in flames, said Federal Aviation Administration spokesman Ian Gregor. From the school, its yellow tail could be seen pointing up from the ground.
The crash caused a brush fire but flames didn't spread beyond the crash site, fire officials said.
The campus was used as a staging area for emergency workers.
Molokai is a mostly rural island of about 7,000 people between Maui and Oahu, where world leaders have gathered this week for the Asia-Pacific Economic Cooperation summit in Honolulu. Antone told the Star-Advertiser that initial indications were none of the four passengers was in Hawaii to attend the summit.
Helicopter tour companies advertise trips to Molokai to see the island's sea cliffs and Hawaii's tallest waterfall. The remote Kalaupapa peninsula on Molokai is where Hawaii exiled leprosy patients between 1866 and 1969.
Blue Hawaiian conducts 160,000 tours each year on all of the Hawaiian islands, Chevalier said.
A Blue Hawaiian helicopter was previously involved in a July 2000 crash that killed seven people on Maui. Pilot Larry Kirsch, 55, and six passengers died when the twin-engine AS-355 crashed into a steep mountainside deep in Maui's Iao Valley.
A National Transportation Safety Board report on that crash said the pilot was responsible. He failed to maintain enough altitude over the terrain amid low-lying clouds, and the helicopter slammed into the side of a ridge in the valley, the report said.
There have been other tour helicopter crashes in the islands over the years.
In March 2007, four people died when a Heli-USA Airways helicopter crashed at Princeville Airport on Kauai.
Three passengers drowned in 2005 after a helicopter crashed into the ocean off the coast of Kauai. The previous year, five people were killed when a helicopter crashed into a mountain on Kauai.