Crews worked Saturday at the Memorial Union at Arizona State University’s Tempe campus after Thursday’s fire charred the building.
Students who left backpacks and other things behind during the evacuation can claim those items Monday.
ASU officials plan to open parts of the building later in the week.
Dozens of workers with Belfor Property Restoration, a company that specializes in property disaster recovery, hauled tables and chairs outside the union Saturday afternoon.
A company representative declined to comment on what the crews were doing.
No one was injured in Thursday’s fire, which forced the evacuation of about 5,000 people.
Tempe Fire Department spokesman Phil Rohe declined to comment Saturday on why investigators are calling the fire “suspicious.”
He said fire officials finished their investigation at the site shortly after 5 p.m. Friday and released the building back to ASU so the university could evaluate damages and begin repairs.
“We are not going to the point where we are calling it arson,” Rohe said.
“But we are now following up leads,” he said.