A helicopter went down on Fort Street just before 3:30 p.m. Wednesday.
The chopper ended up on Fort Street between Kukui Street and Beretania Street.
At least one vehicle was badly damaged in the landing.
A 30-year-old woman piloting the helicopter and a 71-year-old who was a passenger both refused medical treatment.
According to the pilot of the chopper, Mauna Loa Helicopters was hired by Aerial Photography Hawaii to help them shoot video.
Aerial Photography Hawaii specializes in panoramic imaging, virtual tours and oblique-scenic photography, according to its website.
Police closed the Pali Highway near Kukui Street, Fort Street and part of Beretania Street in that area during that investigation.
A source said the Robinson R22 experienced catastrophic engine failure.
The chopper was manufactured in 1992, according to records with the Federal Aviation administration.
Records show the chopper received its air worthiness certificate in February, which is good until 2016.
A source tells KITV that these Robinson R22s must receive a complete overhaul after 2,200 hours of flight.
Those FAA records will all be part of a National Transportation Safety Board investigation in the coming weeks and months.
Police kept the roads closed during the investigation.
The chopper was taken away on a flatbed truck at 6:37 p.m.