KUNIA, OAHU (HawaiiNewsNow) - Witnesses said the small plane that crashed in Kunia on Friday night appeared to be having engine trouble before it plowed into a mountainside.
All four people on board the single-engine plane were killed.
"I heard it come over the mountain and it was flying kind of low and my friend was like 'that's pretty low,'" said witness Aaron Alder.
"Then it was making a turn to go back over (the mountain) but it ... wasn't making a smooth turn. Then it went over there and all we heard was a 'boom' then the sound just went off."
The NTSB is investigating the cause of the crash, which happened in a heavily-wooded area above Kunia farmland.
Farmer Pedro Abad, Jr. said he noticed the small plane, and he said it appeared to be experiencing engine trouble.
"It was just going down and it looked like the engine was not working good," he said.
Witnesses say it was just before sunset is when the plane disappeared.
"We were just praying it wasn't a crash," Alder said.
It's unclear if the plane witnesses described was the Beech 19A aircraft that Dean Hutton piloted that same Friday evening.
His uncle said he was taking three of his buddies out on a sunset flight.
In addition to Hutton, friends and family identified the those on the plane as Gerrit Evensen, his girlfriend Heather Riley and Alexis Aaron.
According to the FAA, the plane's last communication with air traffic control was at 6:37 p.m.
A friend of Evensen and Riley said the couple was asked to join the trip at the last minute.
"This was kind of a spur of the moment kind of thing," said friend Jacob F.G. Conroy. "They didn't fly often, that's for sure."
Firefighters recovered the victims' bodies from the mountainside on Saturday evening.
Three of them were located inside the downed plane. The fourth body was discovered outside near the wreckage.
Meanwhile, aircraft owner Jahn Mueller issued this statement Sunday:
In a bizarre twist, Mueller also owned another single-engine plane that went up in flames after it crashed near Moanalua Gardens in June.
The three people on board that Piper Cherokee were seriously injured.