The Memorial Union which remained closed for the fifth straight day Monday, as ASU police and University officials continued to investigate the cause of the fire that scorched the building Thursday.
The Tempe Fire Department completed its on-scene investigation Monday, said Mike Reichling, a Tempe fire spokesman.
"We're moving on to the suspect interrogation side," he said. "ASU police is still doing their investigations."
Reichling said Friday that the investigation hadn't found an accidental cause for the fire.
The fire, which began around 1 p.m. Thursday, evacuated around 5,000 students and employees from the MU, originated in a storage area on the second level, Reichling said Friday.
"Anyone could have gotten back there," he said. "Maybe somebody was back there and accidentally set the fire."
Crews have begun to work on reopening the MU, though no specific date has been given.
"They have begun to clean up and repair of the fire and smoke damage," said Sharon Keeler, ASU spokeswoman.
Updating the fire codes for the MU, which was built in 1956, are the University's top priorities, said Leah Hardesty, an ASU spokeswoman, on Friday.
"What's important to remember is we got in there and no one was injured," Hardesty said Friday.
Belfor Property Restoration's national fire disaster team is in charge of cleaning the MU and ensuring it is safe again for students this week, she added.
Flames that rose to 1,200 degrees scoured the building, Reichling said.
"I had seasoned firefighters saying this is the hottest fire they'd ever been in," he said.
While the process for cleaning up the mess continues, some students were able to retrieve missing items at a lost and found set up at the Student Recreation Center Monday.
Events that were scheduled in the MU are still being relocated, including flu shots and a sexual assault and rape prevention forum.
Dan O'Connor contributed to this story.Reach the reporters at: matthew.g.stone@asu.edu and daniel.connor@asu.edu.
