By Nomia Iqbal & Chelsea Bailey, BBC News
Teenager Suleman Dawood, who died in the Titan submersible, took his Rubik's Cube with him because he wanted to break a world record, his mother has told the BBC.
The 19-year-old applied to the Guinness World Records and his father, Shahzada, who also died, had brought a camera to capture the moment.
Christine Dawood and her daughter were on board the Polar Prince, the sub's support vessel, when word came through that communications with the Titan had been lost.
"I didn't comprehend at that moment what it meant - and then it just went downhill from there," she said.
In her first interview, Dawood said she had planned to go with her husband to view the wreck of the Titanic, but the trip was cancelled because of the Covid-19 pandemic.
"Then I stepped back and gave them space to set [Suleman] up, because he really wanted to go," she said.
As well as Suleman and his father Shahzada Dawood, three other people died on board: Stockton Rush, the 61-year-old CEO of OceanGate which owned the Titan, British businessman Hamish Harding, 58, and Paul-Henry Nargeolet, 77, a former French navy diver and renowned explorer.
Speaking of her son, Dawood said Suleman loved the Rubik's Cube so much that he carried it with him everywhere, dazzling onlookers by solving the complex puzzle in 12 seconds.
"He said, 'I'm going to solve the Rubik's Cube 3700 metres below sea at the Titanic'."
Suleman was a student at the University of Strathclyde in Glasgow, in the UK. Businessman Shahzada Dawood, who was British, was from one of Pakistan's richest families.
The family, including daughter Alina, 17, boarded the Polar Prince on Father's Day.
Dawood said they hugged and made jokes in the moments before her husband and son boarded the Titan submersible.
"I was really happy for them because both of them, they really wanted to do that for a very long time," she said.
Dawood described her husband as infectiously curious about the world around him - the kind of person who made the family watch documentaries after dinner.
"He had this ability of childlike excitement," she said.
Dawood and her daughter stayed on board the Polar Prince as the search and rescue mission shifted from hopeful to desperate.
"I think I lost hope when we passed the 96 hours mark," Dawood said.
She said that was when she sent a message to her family. "I said: 'I'm preparing for the worst.' That's when I lost hope."
Alina held out a bit longer, she said.
"She didn't lose hope until the call with Coast Guard. When they basically informed us that they found debris."
The family returned to St John's on Saturday, and on Sunday held a funeral prayer for Shahzada and Suleman. Dawood said she was touched that the Imam said a prayer for all five of the men killed.
Dawood said she and her daughter will try to learn to finish the Rubik's Cube in Suleman's honour, and she intends to continue her husband's work.
"He was involved in so many things, he helped so many people and I think I think that I really want to continue that legacy and give him that platform... it's quite important for my daughter as well."
Dawood declined to discuss the ongoing investigations into the tragedy. But when asked how she and her daughter would find closure she said: "Is there such a thing? I don't know."
"I miss them," she said, taking a deep breath. "I really, really miss them."
This story was originally published by the BBC.