The chopper went down around 4:30 p.m.
Two of the people in the helicopter walked away and two others were taken to the hospital. The two who were hospitalized suffered non-life threatening injuries.
The helicopter was taking off on a sight-seeing tour to the foothills when it crashed.
"It was (a) tremendous great big boom. I'd say it was more of a boom than crashing sound, but a big thud, the whole building shook when it hit," said Howard McClure, who was next door when it happened.
There was a small fire and a fuel leak after the crash, but it was quickly contained, according to authorities at the airport.
"I'd imagine there was a couple of seconds those people inside the airplane had a real problem," said McClure.
"The helicopter again was attempting to take off and they had gotten off the ground, something occurred, they obviously came back to the ground then tipped," said Wendy Forbes with the North Metro Fire District.
The National Transportation Safety Board is investigating the crash.
The helicopter was being used by Rotors of the Rockies.
The owner of Rotors of the Rockies, Michael Fyola, released a statement on Wednesday night:
"It is with deep regret that we report that one of our helicopters has crashed on our ramp. The aircraft was flying sightseeing tours to the foothills. Our thoughts are with the passengers and the pilot. We hope the best for their speedy recovery. Preliminary indications are that all occupants suffered minor injuries. There were four occupants of the aircraft including the pilot. The pilot has been with Rotors of the Rockies for more than 5 years. The aircraft involved was N568TD a 1980 Bell206BIII. The FAA, NTSB and local authorities have all been notified. We defer to them to determine the cause of the accident in due course."
According to an employee with Rotors of the Rookies the three female passengers were from out of town. As of Thursday afternoon the employee told 9NEWS the two women who were transported to the hospital checked out and were heading back home.
Fyola said on Thursday he suspended operations for the day so company could take a closer look at what happened.
"Obviously we have to examine our operation and that's what we are doing today is taking a good look at what happened and how things went down and how our people responded," he said.
Fyola said the pilot in charge of the aircraft at the time of the accident had been flying for Rotors of the Rockies for five years and came on board with several years experience. He was not hurt in the accident.
"As far as accidents go we are just thankful that everybody came out relatively unscathed and I and we hope for a quick recovery for those folks that had some minor injuries," said Fyola.
Rotors of the Rockies opened as a training facility for helicopter pilots in 2001 and expanded its business to include chartered tours three years ago.
Rocky Mountain Metro Airport used to be known as the Jefferson County Airport. It is west of Wadsworth near US-36, south of Interlocken loop.
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