As graduates crossed the stage at the University of Arizona last week, one seat remained notably empty.

Hoi Kei “Patricia” Woo, a recent graduate of the UA’s Master of Science in Business Analytics program, has been missing since late-April, her white SUV found abandoned on Mount Lemmon just days after she was last seen

The discovery of her car, her phone and purse still inside, set off a wave of fear and heartbreak among those who knew her as a brilliant, soft-spoken graduate student with plans for the future and no clear reason to vanish.

As questions continue and official searches wind down, her friends, professors and family are left clinging to hope.

Woo’s white 2019 Volkswagen Tiguan was discovered parked at Windy Point Vista on Mount Lemmon on Cabrillo Highway, in a parking spot facing away from the bathrooms, on Sunday, April 20, two days after her last reported sighting.

A friend of the “student's sister actually found the car up at Windy Point,” said Gray Hunter, academic director for the University of Arizona Eller College of Management’s Master of Science in Business Analytics program.

Hunter first met Woo in the summer of 2023, when she started her master’s program at Eller. He was returning from a family outing on Easter Sunday when he got the call about Woo’s disappearance.

“They kind of started off the friends’ search and notified the police Saturday,” said Hunter. They “called hospitals, called jails. Nothing.”

Woo’s friend, Michelle Thomas, was part of those early searches. It was her sister who discovered the car.

“I placed the missing person’s report in Tucson (on Saturday,) and so the Tucson Police Department was looking into it. And so they're just looking in the Tucson area, they would not have looked up on Mt. Lemmon at all because that’s the sheriff’s area,” she said. It’s “by some miracle that my sister and her husband found the vehicle.”

Thomas met Woo in the summer of 2023 as they were starting a six-week bootcamp at Eller. With only five women in the business analytics program’s small cohort, the group became very close. They were part of a group chat and would get together for weekly lunches or dinners, which Woo loved to attend.

“She’s a very genuine, smart, nice person,” said Thomas. “She’s definitely one of the best people that I've ever known.”

Thomas, who now lives in Northern Arizona, says the two have remained close, celebrating Thanksgiving together in Tucson with Woo, her husband and friends.

Woo, who is from Hong Kong, learned about the UA through an exchange program during her undergraduate education at the Chinese University of Hong Kong.

She met her husband, who is from China, at the UA while playing badminton at the rec center. After graduation, the pair were married in China.

“She was a pharmacist in Hong Kong for a while, and then she said she got tired of it. It got boring,” Thomas said. “So she wanted to switch over to something else and she decided to do the business analytics program.”

During the final semester of her master’s program, Woo split her time between the UA’s Tucson and Chandler campuses, living in Tucson and traveling to Chandler every two weeks to attend two days of class.

After graduating in December, she became a volunteer lab research assistant at the UA while looking for jobs as an international student.

Jeremiah Gaiser worked in the lab with Woo this spring. He says she’s sorely missed.

“In the lab she was a really positive presence. She really enjoys movies. I remember this one day, we were talking about movies, and she had all these movies from Hong Kong that she was really excited to share (with me.) I still have them on my list.”

Gaiser said that the week before her disappearance, Woo talked about her struggles with finding a new job, with her 90-day grace period coming to a close. International students on Optional Practical Training are allowed a maximum of 90 days of unemployment during their OPT period without violating their status.

“I knew Patricia was stressed about her job prospects, which I assured her was insane,” Gaiser said. he’s “very competent.”

In addition to her love of nature, movies and food, Woo made jewelry in her spare time. She and Thomas discussed starting a business together, since Thomas’ work in the industry and have a business of their own.

“She got interested in that,” Thomas said.

While nothing had fully blossomed with the jewelry business, it’s one of the reasons Woo’s disappearance is so confusing to her loved ones: She was actively making plans for the future with the people in her life.

“I was planning to go down (to) Tucson and visit that same week (she disappeared.) She was looking for a job (and) she was meeting with people to find a research position,” Thomas said. “She had plans for the future.”

Hunter is also baffled by her sudden disappearance.

“I had a meeting set with her the following Monday. I was kind of desperately waiting for that meeting and just kind of hoping some sort of miracle is going to occur and she'll pop on it at 1 p.m.,” he said. “Unfortunately, that did not happen.”

Six days after she was declared a missing person, the Pima County Sheriff’s Department released a statement saying they’d “exhausted all resources.” Several days later, the Southern Arizona Rescue Association and sheriff’s deputies were spotted with a large drone, filming over the cliff off of Windy Vista Point.

Police reported that Patricia was last seen wearing a black shirt and pajama pants, which also struck her loved ones as odd.

“I've never seen her go out in public in pajama pants,” Thomas said. “ I don't think of her as a hiker. She's a city girl. She would not have gone out (in public) like that.”

Even more unusual, Thomas said, is that Woo’s phone was still in her car.

“She's a person (who) always responded within like an hour of you messaging her. And if you called her, she usually picked up,” Thomas said, adding that she also “took millions of pictures. Like she filled up her phone. I don't think she would just leave her phone there.”

Two weeks after Woo was reported missing, friends hosted a candlelight vigil in Eller’s McClelland Auditorium, with Hunter asking her husband and family for permission to hold space in her memory.

A few dozen of her friends and professors were on hand, sharing stories about Woo and hoping for her safe return.

“It almost sounds cliché, but it's so abundantly true — being around her and seeing the candlelight vigil was just further confirmation that she inspires care in the people around her,” said labmate Gaiser.

The day after the vigil, Woo’s sister Wendy Woo created a GoFundMe page with a goal of $13,000 to aid in her search and help support their parents, who live in Hong Kong on a fixed income.

“Patricia is an outgoing, intelligent, and deeply cherished woman. She is known for her bright personality, warm heart, and love for nature,” Wendy Woo wrote in the post. “Throughout her life, Patricia has been outstanding in her academic achievements, always striving for excellence and inspiring those around her with her curiosity and determination.”

Some of the money will be used to pay for a private investigator the family has hired, with more than $11,500 raised as of Monday afternoon.

While her disappearance is still an open investigation, there are no leads as to her whereabouts.

Gaiser said he appreciates that the community cares and wants to help, pointing towards an active subreddit thread about the search for Woo.

“What's so weird about disappearing, missing persons is the lack of closure,” Gaiser said.

But for some, that lack of closure and finality is also accompanied by hope.

“Her sudden disappearance has left everyone who loves her devastated and more determined than ever to bring her home,” Wendy Woo wrote on GoFundMe.

Thatcher Warrick Hess is a graduate of the University of Arizona's bilingual journalism program and and Tucson Spotlight intern. Contact him at [email protected]..

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