What began as a Hawaii vacation to celebrate his promotion ended in a fatal tour helicopter crash for Canadian business executive Stuart Robertson and his longtime partner, Eva Birgitta Wannersjo.

Robertson had received a major promotion at his technology management firm, Quartet Service in Toronto, and decided to take a trip to Hawaii with Wannersjo, the firm’s chief executive officer, Robert Bracey, said.

"He wanted to take a break and come back here," Bracey said.

"He was a great guy. … They (Robertson and Wannersjo) were free spirits. They loved each other."

The National Transportation Safety Board is continuing its investigation into the cause of Thursday’s crash, on a hillside about a quarter-mile mauka of Kilohana Elementary School on Molokai.

The fiery crash that killed five people sent a plume of smoke skyward that was visible for miles.

Killed were Robertson, 50; Wannersjo, 47; pilot Nathan Cline, 30, of Kihei; and Pittsburgh honeymooners Michael Todd Abel, 25, and his wife, Nicole Bevilacqua, 28.

Employees at Kott Lumber, where Wannersjo worked in accounting, were saddened by the news of her death, said Supinder Babra, a Kott manager.

Babra said Robertson and Wannersjo were a happy couple and had been together for 15 years.

"Birgitta was dedicated, honest and a wonderful person to work with," Babra said.

The five left from Kahului Airport on a Blue Hawaiian Helicopters tour to West Maui and Molokai when the helicopter crashed at about 12:15 p.m. Thursday.

A resident said heavy rain squalls hit the area before the crash. Another resident said the helicopter sounded like it was trying to make an emergency landing.

Bevilacqua and Abel, who were married Nov. 5 in Pennsylvania, planned to spend their vacation on Maui and Hawaii island during their two-week honeymoon in Hawaii.

They met while working as engineers for Westinghouse’s nuclear services product line in Cranberry Township, Pa., Abel’s father said.