DALLAS (AP) — Among the 16 people who were killed in a hot air balloon crash in Texas over the weekend were a couple celebrating their 17th wedding anniversary and a researcher whose work focused on treating burn victims, grieving family members said.

Authorities haven’t released the names of those who died when the balloon struck power lines and crashed Saturday morning near Lockhart, which is 30 miles south of Austin. But some family members have come forward to say their loved ones were aboard and to speak of the growing dread they felt in the hours after the crash as their frantic texts and voicemails went unanswered.

Josh Rowan said his brother and sister-in-law, Matt and Sunday Rowan, were among those killed. The couple, both 34, grew up in College Station and had been friends since high school, and had just gotten married in February, he said.

“All of us were sort of calling them and texting them and messaging them and just trying to get anything back and just sort of time went on and we didn’t hear anything back,” Rowan said, noting that authorities later told the family his brother and sister-in-law were aboard the balloon.

Matt Rowan was a researcher and scientist at Brooke Army Medical Center who served as chief of one of its research centers. His research centered on treating burn victims, and he had also taught college chemistry.

Sunday Rowan worked at a clothing store and had a 5-year-old son. Brent Jones, the boy’s father, told Dallas television station KDFW that Matt Rowan was an amazing man and that Sunday Rowan was “obsessed with her son’s happiness.”

“They were really happy and they were in love and they were really starting a life together. They were amazing people and they were full of life and full of joy,” Josh Rowan said.

Joe and Tresa Owens took the balloon ride as a belated anniversary present to themselves, his sister, Angie Nadolny of Mattoon, Illinois, said by phone Monday. The couple had been married 17 years and lived in Brookshire, west of Houston.

Nadolny said her brother posted a photo on social media saying he and his wife were about to go on a balloon ride and giving the same launch location as the one used for the ride that crashed. She said she and other family members kept trying to call her brother, but they never heard back.

She also said she’s grown frustrated that authorities haven’t revealed the identities of the victims in the crash, which is being investigated.

“No one at all, as far as any authorities, can tell me what happened to my brother,” she said.

Nadolny said her brother, who was 42, was a butcher at the H-E-B supermarket, and that he was a warm man who made friends easily.

“He was a hard worker and loved his family very much,” she said.

Tresa Owens worked at a daycare center in the Houston suburb of Katy. Cheryl Myers, the assistant director of Tiger Land Child Care, said Tresa Owens was a leader in their infant classrooms for more than 20 years.

“She knew what she was doing. She knew how to make things work. She was great with the parents,” Myers said.

The daycare center released a statement saying that Holly Smith Huckabee, the mother of one of its teachers, was also killed in the balloon crash. A man who answered the door Monday at Huckabee’s home in Katy said the family didn’t want to speak.