"I took a couple of steps, running towards the road and ... looked at Rachel, sort of over my shoulder. She was standing still, just at that very moment I saw a large slab of concrete fall right on top of her.
"This was followed immediately by a large amount of rubble which also fell on the spot where Rachel had been standing."
The pair were near the end of their round-the-world trips, and were due to fly to Australia and then on to Asia on February 23.
They went to Southern Ink tattoo parlour on their last full day in New Zealand, booked a double appointment for 3pm, and decided to drop off a rental car before returning for their appointment.
Miss Conley planned get lyrics to The Beatles song 'All You Need Is Love' tattooed on her back.
But when they left the parlour at 12.51pm, the killer quake struck.
Ms Kinder recalled: "Just at that moment, the earthquake struck. As it started shaking, I looked at Rachel and I saw her standing still.
"I saw her torso hit and then she had immediately become buried.
"As soon as I saw her get hit I knew instantly that she would have been killed."
Miss Conley's mother Deb today told APNZ today that she welcomed the inquiry process, and had no interest in laying blame on anyone for her daughter's tragic death.
Speaking from her home in Dayton, Ohio, she said: "I have watched some of the live feed hearings and appreciate the process. The excellent communication and organised detail impresses me and has helped bring closure to all the questions that I have ever had.
"I understand this is difficult for everyone. I am not looking for fault and have no interest in blame. There are reasons things happen that we will never understand.
"Rachel was exactly where she wanted to be - living life to the fullest - fuller than 20 people do in one lifetime."
Mrs Conley said her daughter had met "an awesome and eclectic" group of people on her travels in New Zealand, and hoped that she could one day visit the country herself.
"It has been the hardest year of my life but God, great family and friends help us carry forward," she said.
The royal commission of inquiry today heard that the two Colombo St buildings had been highlighted as "earthquake prone", but engineers ruled them safe to occupy after the mag-7.1 September 4, 2010 earthquake.
Structural engineer Noel Hanham conducted an assessment for the building owners after the September shake but admitted he was unclear about the building's history - even to the point that he didn't know when it was built.
He told the hearing: "In this case, I'm at a loss to know exactly when this building was constructed. Various reports refer to 1900s, and yet one of the council reports talks about it being built in 1923."
His appraisal was based on a basic inspection of the building carried out on the instructions of Hiren Patel, owner's representative for 595 Colombo Street.
"They did not want a detailed inspection," Mr Hanham said.
And while he determined that its condition had not deteriorated after the September shake, he admitted that the February quake, which claimed 185 lives, was "a complete wake-up call to what was out there".
Meanwhile, structural engineer Kevin Simcock who inspected 595a Colombo St in 1999 said that even if the building had undergone a full strengthening upgrade, it could still have failed in the disaster.
"My belief is that February was a very unique event. If that facade had been tied back to the building at full code, it still had potential to fall - such were the forces in February," he said.
Peter Smith, a structural engineer who reviewed the performance of the buildings for the royal commission, concluded that lessons on URM buildings should be learned from the disaster.
"If we learn anything from the Christchurch event, hopefully it's that... any area of URM buildings where facades are not secured, pose a significant risk to the public during a significant earthquake."
Mr Smith also said the system of assessing how buildings are inspected after a major earthquake needs overhauling, especially when looking at URM buildings which have "weak elements" like facades.