WEST LAFAYETTE, Ind. -- Hundreds of volunteers joined police officers Thursday in an hours-long search around the Purdue University campus for a freshman missing since the weekend.

Wade S. Steffey, 19, of Bloomington was last seen early Saturday leaving a party at the Phi Kappa Theta fraternity house on the north side of campus, police said.

Searchers spent Thursday checking campus buildings, along with places such as the campus golf courses, Purdue's horticulture park and some near-campus neighborhoods and wooded areas. Maintenance workers checked the utility tunnels under the university.

The search concluded at nightfall without Steffey being found, Purdue spokeswoman Jeanne Norberg said.

"It's really humbling and very heartwarming to see all of the outpouring of support for Wade," said his mother, Dawn Adams. "I'd like to say it's overwhelming, but that's not even the right word."

Police said Steffey left his residence hall Friday evening, and that shortly after 8 p.m., a $50 withdrawal from his bank account was made from an ATM at a campus dining hall.

His cell phone was last used at about 12:30 a.m. Saturday, police said.

"From everything that we can gather through our investigation, Wade is a straight-A student, well-liked, very studious type of student who wouldn't just get up and take off without notifying friends, roommate or family," campus police Capt. John Cox said.

Steffey, a graduate of Bloomington South High School, is studying aviation technology on a full scholarship and did not have a car at Purdue, Adams said.

His parents and friends tried to remain hopeful Thursday that he would be found safe.

"It would be really helpful to have some kind of resolution one way or another," Adams said. "The best thing would be to find him and that he's OK. It's really hard to consider the possibility that he might be suffering or in pain."