University of Michigan sophomore Lucas Mattson, 19, was found dead Saturday after a daylong search that began when he left a fraternity party around 1 a.m. Friday wearing only a T-shirt and jeans as temperatures hovered near zero, authorities said. He was discovered in a residential area near campus in the 1900 block of Cambridge Road following a coordinated search by Ann Arbor police and university officers.
Officials said there were no obvious signs of trauma and that foul play is not suspected, pending an autopsy by the Washtenaw County Medical Examiner’s Office. The case has gripped the campus, coming amid a blast of arctic air that blanketed southeast Michigan. Police said Mattson, an engineering student, was reported missing roughly 15 hours after he was last seen walking alone near Hill Street. The university’s Division of Public Safety and Security joined city officers and deployed a drone unit as part of the search. Administrators expressed condolences to Mattson’s family and urged the community to avoid speculation while the investigation proceeds.
Authorities said the sequence began shortly after 1 a.m. Friday when Mattson was seen leaving a gathering at a fraternity house on Hill Street. Witnesses told investigators he was dressed in a light-colored T-shirt, jeans and white sneakers and did not appear to be wearing a coat despite subfreezing wind chills. He was later reported missing to city police at about 4:30 p.m., prompting a search that extended through the night. Officers canvassed blocks between Hill and Oxford streets and later shifted toward the Cambridge Road area. “There were no signs of foul play at the scene,” Ann Arbor police said in a brief statement, adding that the cause and manner of death would be determined by the medical examiner.
Investigators documented the site where the body was found around midday Saturday and notified next of kin. Police said they are reviewing security video, doorbell-camera clips and any digital location data to trace Mattson’s movements after he left the party. The search included ground teams and a university police drone unit that focused on low-visibility areas along residential corridors near campus. Temperatures in Ann Arbor dipped to around 0 degrees with wind gusts in the early morning hours Friday, conditions officials described as “extreme cold.” Authorities have not released additional medical details and declined to say how long Mattson may have been outside before he was found. The department said updates would follow once autopsy results are complete.
University staff set up support services for students as news spread through dorms and apartment houses over the weekend. Interim leaders issued statements acknowledging the shock and urging students to check in with each other. Residents in the neighborhood said emergency vehicles came and went through Saturday as crews cut across sidewalks that remained glazed with hard-packed snow. A small cluster of flowers appeared near Cambridge Road by evening. “It’s a heartbreaking loss,” a neighbor said, recalling the flurry of patrol cars that converged on the block around midday.
Search teams began by retracing steps from Hill Street, a stretch lined with student housing and fraternity properties, then widened concentric zones block by block. Officers checked yards and alleys, used thermal imaging from a drone and requested any private camera footage from the overnight hours. University police said the drone unit helped map areas with heavy tree cover and poor sight lines. City crews also cleared sidewalks to aid the search as temperatures remained bitterly cold. Police emphasized that early findings do not suggest an assault or a hit-and-run, and that no suspects are being sought.
Classes remained in session Monday, but some instructors postponed quizzes and labs as students gathered at counseling offices and campus spaces set aside for quiet reflection. Mattson, originally from Alaska, had been studying engineering and was described by classmates as diligent and quick to help with problem sets. Friends said he was not affiliated with the fraternity where the gathering took place but knew attendees through coursework and clubs. On social media, former teachers and family friends posted remembrances and condolences, many noting the timing during a dangerous cold snap across the region.
The investigation now moves to the medical examiner’s suite, where pathologists will evaluate hypothermia as a possible factor alongside other conditions. Police typically request toxicology samples in sudden, unexplained deaths to provide a fuller picture of the hours before a person was found. Authorities said they expect preliminary autopsy information to be available in coming days, with full results taking longer. In the meantime, detectives will continue to collect statements from party attendees and residents along the route Mattson may have walked, seeking to close gaps in the timeline.
Ann Arbor police said they plan to summarize the case for release once the medical examiner issues findings and next of kin have reviewed them. University safety officials said they are coordinating with city authorities and will adjust campus communications if new information emerges. Administrators said support services will remain available this week for students coping with the loss, and that any memorial plans would be shared after consultation with the family. As of Monday afternoon, there were no additional updates on the investigation’s status.
By Monday evening, police maintained that foul play is not suspected and that the autopsy will guide the next steps. Officials said a further update is expected after the medical examiner issues preliminary findings.
Author note: Last updated January 27, 2026.