One of the victims, Becky Dobson, 27, had dreams of becoming a veterinary nurse, while a newlywed couple have been left fighting for their lives.
Becky, the youngest victim, died in Saturday’s tragedy along with Jason Hill, 32, and Stuart Hill, 30.
Three fellow Brits – newlyweds Ellie Milward, 29, and Jonathan (Jon) Udall, 32, and Jennifer Barham, 39 – survived and were airlifted to hospital in a critical condition, along with American pilot Scott Booth, 42.
It was understood they were on holiday in Las Vegas when they went on the helicopter tour.
Becky was a receptionist at Vets4Pets in Worthing, West Sussex, and previously lived and worked in Sydney, Australia, before returning to the UK.
It is understood Jason and Stuart Hill were also from Worthing.
In an employee profile on the Vets4Pets website, Becky described how she “loves” animals and wanted to be a veterinary nurse.
She wrote: “I’m a very outgoing person and I’m always up for having fun!
“My favourite things to do are, spending time up the yard with my 4 legged, beautiful boy, Buddy the Irish sports horse, seeing friends and family and I also love to travel the world and explore what is out there beyond good old Worthing.
“I love my job and I am hoping to one day fulfil my dream of becoming a Veterinary Nurse!”
She had previously worked as an au pair in Sydney, according to her Facebook page.
Heartbroken friends paid tribute to her on Facebook, with one writing: “She was one of the nicest people I’ve ever been lucky enough to meet and call my friend.
“Rest in peace lovely, you have no idea how much you’ll be missed.
“My thoughts and love are with your family and everyone else involved.”
Newlyweds Ms Milward and Mr Udall, who got married just three months ago, remain in hospital with serious injuries.
Mr Udall’s father, Philip, said Ms Milward is stable and wasn’t as seriously injured as her husband.
He said the couple were with a group of friends all believed to be from Sussex.
He told MailOnline: “Jon is still alive and breathing, we are so thankful for that. He’s in a serious but stable condition in hospital but we hope he’s going to be ok.
“The Foreign Office have given us a lot of help and we are still in contact to find out what’s going on.”
Witnesses say survivors ran from the wreckage moments before it exploded into flames.
A witness said he “just lost it” after seeing an injured woman stagger out of the flames, collapse and scream the name “Jason”.
Three Brits were killed in the fiery crash and three others survived but were critically injured, along with the American pilot, spending about nine hours at the bottom of a rocky gorge before they were finally airlifted to hospital.
Traumatised witnesses described horrific scenes in the aftermath, telling how two women emerged from the helicopter and then ran away screaming just before it “blew up”.
The injured survivors spent about nine hours in the canyon, as fierce winds, rugged terrain, dust and darkness hampered the rescue effort.
The Eurocopter EC130 helicopter was operated by Papillon Airways, an aerial sightseeing company that gives tours of the natural landmark in northern Arizona and other locations.
In 2001, the company was involved in a sightseeing helicopter crash in the Grand Canyon that left six dead, and has been investigated after at least three other fatal incidents in the last 20 years, it was reported.
Teddy Fujimoto was taking photos of the breathtaking spot – where many newlyweds pose for wedding snaps – when he saw the aftermath of the crash.
He told 12 News: “It hit the side and then I heard that it kind of crashed and rolled and then it just kind of blew up.”
Pilots and passengers from other helicopters ran towards the crash site as smoke billowed into the air.
They found the burning wreckage about 600ft below in a valley.
Mr Fujimoto, who was photographing a wedding, told KSNV: “I saw these two ladies run out of it, and then an explosion. One of the survivors … looked all bloody. Her clothes probably were burnt off.”
He added: “The ladies were screaming. … It was just horrible.”
Mr Fujimoto said there was “a lot of chaos going on” and shocked witnesses felt helpless.
He said people climbed down a steep rocky canyon help the victims, but it was a “dangerous and mazy” descent. By the time the emergency services arrived, most of the fire was out, he added.
Witness Lionel Douglass had been attending a wedding on a bluff about 1,000 yards away from where the helicopter burst into flames.
He told ABC News: “I had taken my phone and I was zooming in to see if I could see anybody and a lady walked out of the flames and I just lost it.”
The woman appeared to be disoriented as she staggered out of the wreckage, and then collapsed to the floor and began screaming the name “Jason”, he added.
Mr Douglass said he saw the helicopter plummet from the sky after doing two complete circles as if the pilot was looking for a spot to land.
He added: “It fell down between the mountains, the tail broke in half, it hit the bottom and it was the biggest explosion you ever heard and then flames like you never seen before.”
The initial explosion was followed by five or six other blasts, he added.
Photos of the crash scene, near Quartermaster Canyon on the Hualapai Nation Indian Reservation, showed flames and dark smoke rising from rocky terrain.
One appeared to show a female survivor, wearing jeans and a white top, fleeing the scene as the fire rages behind her.
The helicopter went down on the west rim of the canyon at about 5.20pm on Saturday. The survivors were airlifted to hospital on an Air Force helicopter at about 2am on Sunday, the Las Vegas Review-Journal reported.
Rescuers stabilised them but had to wait for conditions to improve before they could be flown out of the canyon and taken to University Medical Centre in Las Vegas, Nevada.
Hualapai Police chief Francis Bradley Snr said of the survivors: “I’ve seen a lot of accidents, especially those involving car crashes and other types of traumatic injuries, and … the will to survive kicks in.
“And as you know, it’s a fight or flight syndrome that we have in every one one of us, and I’m sure that had a lot to do with their survival.”
He said the tour originated in Boulder City, Nevada, just outside of Las Vegas, and a storm was rolling into the area at the time of the crash.
Mr Bradley described the weather conditions as “not normal”, but said no flight restrictions were in place.
He told reporters: “It’s a very tragic incident.
“Yesterday, we were hampered by severe weather conditions, we had gusts up to 50mph. The terrain where the crash occurred… is extremely rugged.”
Rescuers were dropped into the canyon by helicopter and then hiked to the crash site.
Pilot Mr Booth, who was also in a critical condition, was said to have suffered severe injuries to one of his limbs.
Tourist Kaitlyn Rodriguez, who was on a different helicopter that had landed in the area, told how her mum climbed down to the crash site and helped the victims.
She wrote on Facebook: “I was on this tour and moments after our helicopter landed, witnessed the crash. My amazingly brave Mother, along with several others, trekked down into the ravine to assist the survivors.
“We were stranded in the Grand Canyon for hours , my Mom being at the bottom administering medical attention to the survivors for over 10 hours.
“So very proud of her and all who helped the victims of the crash. Such a tragic accident.”
Federal Aviation Administration spokesman Allen Kenitzer said the aircraft sustained considerable damage in the crash.
Papillon Group chief executive Brenda Halvorson said in a statement: “It is with extreme sadness we extend our heartfelt sympathy to the families involved in this accident.
“Our top priority is the care and needs of our passengers and our staff.”
Mr Bradley told CNN that first responders had difficulty reaching the four survivors, which included the pilot, because of windy, dark and rugged conditions. Rescuers had to use night vision goggles to find their way around after the sun went down.
The circumstances surrounding the crash, which happened about 60 miles west of Peach Springs, Arizona, are currently unknown.
The FAA and the National Transportation Safety Board are leading the investigation. All tour flights were grounded following the crash.
A Foreign Office spokeswoman said: “We are providing support to the families of six British visitors involved in a helicopter accident at the Grand Canyon on February 10, and we are in close contact with the US emergency services.”
With depths of more than a mile, the Grand Canyon is one of the most popular tourist destinations in the world.
The Papillon Airways website says it flies roughly 600,000 passengers a year around the Grand Canyon and on other tours. It has almost 50 helicopters in its fleet.
It describes itself as the “world’s largest aerial sightseeing company” and says it offers “the only way to tour the Grand Canyon”.
Helicopter crash attorney Gary Robb said it could take at least nine months to determine a probable cause.
He told the Review-Journal: “It’s too early to speculate, but early indications suggest that perhaps heavy gusts could have been a factor that drove the aircraft to strike a wall of the canyon.
“The other possibility is some sort of in-flight mechanical issue including an engine problem or main roter blade fracture or defect. You also cannot rule out human error whether it be some sort of pilot incapacitation or neglect.”
Mr Robb represented the lone survivor of the 2001 crash involving Papillon, which killed five passengers and the pilot near Meadview, Arizona. The probable cause was determined to be pilot error.
In that incident, the helicopter crashed on its way back to Las Vegas’ McCarran airport after touring the west Grand Canyon and stopping at a landing site in Quartermaster Canyon.
Mr Robb said Papillon has been subject to about a dozen aviation probes by the NTSB since the deadly 2001 crash, and has made a “concerted effort to improve and overhaul their safety.”
Hundreds of helicopters take tourists over the Grand Canyon every day. The crowded airspace is “a recipe for disaster”, Mr Robb told USA Today.
Papillon has been investigated after at least three other fatal incidents in the last 20 years, the newspaper reported.
In 2014, one of the firm’s pilots died when he was struck by rotor blades when he got out of a running helicopter to go to the toilet, ABC 15 reported.
A pilot was killed and an instructor was seriously injured when a Papillon helicopter hit a tree in 1999.
Meanwhile, the FAA wants tougher regulations for tour helicopters at the Grand Canyon following a number of crashes.
It had already banned aircraft from flying below the canyon rim and implemented a mandatory 500ft buffer zone between aircraft and any obstacles.