A mother who worked in the Hawaii tourism industry and contracted a mysterious fatal illness while vacationing in Fiji is being remembered as a bright young leader who loved her family.

University of Hawaii graduate Michelle Calanog Paul, who along with her husband, David, died late last month after becoming sick from an unidentified illness, had a 2-year-old son and a daughter David Paul had from a previous relationship.

“They are remarkable people and such a loving couple who cares immense­ly about family, especially their children,” said Calanog Paul’s sister-in-law Tracey Calanog. “It has been a very emotional week.”

The couple, who were living in Fort Worth, Texas, arrived in Fiji on May 22 and were taken to a hospital, where their conditions worsened despite medical care, according to Fiji’s Ministry of Health and Medical Services. They died within a few days of each other, authorities said.

Calanog Paul worked for booking.com while in Hawaii and was active in the tourism industry’s charity walk and mentoring of other young tourism leaders, said Mufi Hannemann, president and CEO of the Hawai‘i Lodging and Tourism Association, adding that she was the first co-chairwoman of the organization’s mentoring group, Hospitality’s Young Professionals & Entrepreneurs, from 2016 to 2017. She also was a senior sales manager from 2012 to 2014 for the Courtyard by Marriott, an assistant outlet manager from 2011 to 2012 with Westin Hotels & Resorts and a management trainee in 2011 at Starwood Hotels & Resorts Worldwide Inc., according to her LinkedIn online profile.

“She was one of our bright young hospitality leaders,” Hannemann said. “She was one of those that grasped it right away and stepped up to the plate. Today it still exists thanks to her leadership. She was young but very mature and carried herself very well. I’m very sad about the whole experience. It’s just very tragic, very unfortunate. We’re going to miss her.”

Kevin Baay Rivera, a reservations manager for the Hilton Garden Inn Waikiki Beach, who was also part of Hospitality’s Young Professionals committee, said Calanog Paul was a hardworking mother who loved spending time with her family.

“She was a person that you can count on. She would be the person that would push the new committee members and drive them to give ideas,” he said. “If we had an event, she’ll always be there to be a lending hand.”

Authorities in the South Pacific country said they are working with police forensics, the World Health Organization and the U.S. Centers for Disease Control and Prevention to determine what caused the deaths. The ministry said it had put in place public health measures, but it didn’t immediately identify what those were.

Paul was an Air Force veteran, and Calanog told Texas television station WFAA that the couple was physically fit.

Calanog said the couple loved to travel and had been organizing the Fiji trip for some time: “They were planning an amazing vacation,” she said.

She said the couple’s children were with relatives.

The U.S. Embassy in Fiji said in a statement it had been working closely with the Fijian government, police and health officials for more than a week to investigate the deaths.

“We appreciate the efforts made thus far by the Fijian authorities and stand ready to provide further assistance, if requested,” the embassy said. “At this point, we are not aware of any specific public health threat to the community.”

Fiji is home to more than 900,000 people and is a popular tourist destination due to its warm climate, white-sand beaches and coral reefs.

Associated Press contributed to this report.