Cal Poly honors Sean Hillman with posthumous degree

Published 1:30 am Tuesday, June 30, 2026

Three years after Sean Ogawa Hillman was struck and killed while bicycling near his college campus, his parents walked across a Cal Poly commencement stage to accept the degree he would have earned this month, according to a release from the university.

Hillman, a Vashon High School graduate and first-year architectural engineering student at California Polytechnic State University in San Luis Obispo, California, died April 24, 2023, three days after he was struck by a pickup truck while riding his bicycle near campus. He was 20.

On June 14, Hillman was honored during commencement for Cal Poly’s College of Architecture and Environmental Design, according to the university. His parents, Carl Hillman and Mayumi Ogawa, accepted his bachelor’s degree in architectural engineering from Cal Poly President Jeffrey D. Armstrong.

Had he lived, Hillman would have graduated with the Class of 2026.

The recognition came during a day of tributes for Hillman, whose short time at Cal Poly left a lasting impression on classmates, professors and the university’s architectural engineering program.

Earlier that day, during a ceremony for graduating architectural engineering students, Hillman was posthumously inducted into the Order of the Engineer, honored with the dedication of a student-built structure near the Architectural Engineering Department, and remembered through the creation of a new student leadership position meant to help first-year students feel welcome.

That role, a first-year representative position on the board of the student chapter of the Structural Engineers Association of California, was created in Hillman’s memory, Cal Poly said.

Dan Carney, chair of Cal Poly’s Architectural Engineering Department, said the position reflected the way Hillman had connected with other students during his first year.

“Sean was one of those students who sat up front, made sure that all the other freshmen were engaged and made sure that he found a way to have the freshman class part of the program,” Carney said in remarks provided by Cal Poly. “Going forward, the first-year representative will make sure that other freshmen feel welcome in the class.”

Hillman was born in Seattle and moved to Tokyo with his mother when he was 5. At 15, he moved to Vashon to live with his father. On the island, he attended Vashon High School, played on the golf team, worked at the Vashon Community Pool, took part in the Vashon Island Fire Explorers program and earned an associate degree through Running Start while also working several jobs, including at May’s Kitchen + Bar and with Ed Palmer Construction.

At Cal Poly, Hillman studied architectural engineering and was involved in campus life, including the scuba diving and hiking clubs. He was critically injured April 21, 2023, in a collision on Grand Avenue at Fredericks Street, about three blocks from the eastern entrance to campus, according to Cal Poly. He died three days later, surrounded by family members who had traveled from Vashon and Japan to be at his bedside.

Professor Emeritus Al Estes, a retired Architectural Engineering Department chair, taught Hillman in an introductory architectural engineering class and was among the first faculty members to know him.

“I wish that Sean was here wearing a green graduation robe,” Estes said, according to remarks provided by Cal Poly. “But we all know that we can’t bring him back. And I can only imagine the sense of loss that you still feel. So what I hope you get out of today’s festivities is some comfort, some closure and proof that we also miss Sean.”

A permanent gathering space dedicated to Hillman now stands near Cal Poly’s Engineering West Building. The structure, called Sotto L’Ulivo, was designed and developed over six years by four architectural engineering senior project teams, with guidance from Professor Craig Baltimore, the university said.

The shade structure features a hyperbolic roof — a complex geometric form that curves upward in one direction and downward in another, creating a saddle shape. Its dedication on June 14 marked both the official opening of the space and its dedication in Hillman’s memory.

Baltimore described the project as the product of “five years, four different senior projects, three different department heads, two sets of office administrators, and one kick-ass project.”

“A beautiful tribute to Sean,” he said in remarks provided by Cal Poly. “Beautiful space as an extension of the ARCE office. A beautiful example of Learn by Doing in a beautiful place.”

Graduating senior Makayley Washburn, the project manager for the team that completed the structure, said Hillman’s classmates were proud to dedicate the space to him during what would have been his graduation year.

“Sean was our classmate,” Washburn said, according to Cal Poly. “He was outside ARCE 106 with us. He was in Design Village with us, and we have some memories of him. We are just so incredibly proud to be the ones to dedicate this space to Sean.”

Washburn also remembered Hillman as someone who helped create community among his classmates, including through a group Snapchat for architectural engineering students.

“That’s how I remember Sean — representing community and involvement in the ARCE program,” she said.

Hillman’s classmates had previously honored him shortly after his death during Cal Poly’s Design Village, a first-year architecture tradition in which students design, build, transport and live in inhabitable structures in Poly Canyon. After Hillman died, some students wore green in his honor, printed his name on their structures and held a remembrance during the event. His hammock was also turned into a memorial, according to the university.

At the dedication ceremony this month, Carl Hillman thanked Cal Poly’s students and faculty for the care they had shown his family since Sean’s death.

“I just want to say Sean loved this school, and the school has been outstanding through this whole process,” he said, according to remarks provided by Cal Poly. “This was a worst-case scenario on so many levels, and the school just has been so supportive, and the students have been so supportive.”

He said the compassion shown by Hillman’s dorm mates, classmates and faculty had helped ease the family’s grief.

“The emotional intelligence that I see around this campus is just incredible,” he said. “And it’s been a true inspiration. It’s definitely made this grieving process a lot easier.”