A couple are among three British tourists killed in a helicopter crash in the Grand Canyon.
Becky Dobson, 27, Stuart Hill, 30, and his brother Jason Hill, 32, died in Saturday's crash, Hualapai Police said.
Three other Britons and the pilot were injured on the tour of the canyon but they were not rescued until some eight hours later on Sunday morning.
Ms Dobson's father, Peter Dobson, told the Press Association his daughter was "full of life" and "always happy".
The group were away celebrating Stuart's 30th birthday, Mr Dobson said.
He added the couple were "really happy together" and "just enjoyed being with each other".
"The whole thing is just terrible."
Britons Ellie Milward, 29, Jonathan Udall, 32, and Jennifer Barham, 39, were injured in the crash, along with pilot Scott Booth, 42, police said.
Witnesses told local reporters they had seen survivors running away from the crash site and shouting.
It is not clear what caused the crash and witnesses say rescue efforts have been hampered by high winds.
The helicopter crashed on Saturday evening and survivors were not rescued until the early hours of Sunday morning.
The youngest of the victims, Ms Dobson, worked as a veterinary receptionist for Vets 4 Pets in Worthing, West Sussex.
In her profile on the practice's website, she described her love for animals, as well as her dream of becoming a veterinary nurse.
"I also love to travel the world and explore what is out there beyond good old Worthing," she said.
The practice paid tribute to Ms Dobson, saying her colleagues were "devastated" by her loss.
Jason Hill worked as a corporate lawyer for Shoosmiths LLP in its Milton Keynes office.
The firm's chief executive, Claire Rowe, said he was well respected and loved by all those who worked with him.
"He was hardworking, full of energy and enjoyable to work with, and we are greatly saddened by the news of his death and that of his brother Stuart," she added.
Gabby Hart, a local news reporter for the station KSNV, said it had taken more than eight hours for the survivors to be removed from the site because of the terrain and high winds.
She told BBC Radio 5 Live: "We are told by witnesses and also by rescuers that people were trying to help once they saw this accident happen, they couldn't get down to the helicopter quick enough.
"They [the survivors] had to receive care there on site until emergency crews were able to remove them from the scene."
The chief of the local Hualapai Police, Francis Bradley, called the incident "very tragic" and described the terrain as "extremely rugged".
He added rescue efforts had been hampered by severe weather conditions and gusts of up to 50mph.
In a statement, Brenda Halvorson, the chief executive of the helicopter company involved - Papillon Airways - said the company extended its heartfelt sympathy to the families of the dead and injured.
On its website, Papillon calls itself "the world's largest aerial sightseeing company" and says it flies more than 600,000 people a year.
The Grand Canyon, which is more than 1.6km (one mile) deep, is one of the most visited tourist attractions in the US.
A UK Foreign Office spokesperson said: "We are providing support to the families of six British visitors involved in a helicopter accident at the Grand Canyon on 10 February, and we are in close contact with the US emergency services."