The two-alarm fire that destroyed part of the old Aerospace and Mechanical Engineering building Sunday is moving closer to being classified as an arson.

Tucson Fire Department officials and agents from the Bureau of Alcohol, Tobacco and Firearms felt "all but certain" that the fire was intentionally set, said Herbert Wagner Jr., assistant director of Risk Management and Safety Department.

"There were several points of origin," he said. "Plus, this looked like a speedy fire."

Wagner said natural fires usually smolder and activate smoke alarms before flames appear. This fire did not.

Sgt. Brian Seastone said TFD has turned the case over to the University of Arizona Police Department, which will continue the arson investigation.

"We have no suspects," he said. "We are waiting for laboratory analysis and following up on leads."

Seastone was unsure about any motives behind the blaze in the building at 1302 E. North Campus Dr.

"There is nothing significant that we know that would (cause someone to) target this particular building," he said.

Preliminary damage estimates range from $100,000, as estimated by the state Adjuster's Office, to $250,000, from Joseph Humphrey, AME department head.

Steven C. Holland, director of Risk Management, said the reason behind the lower estimate is that some equipment, such as computers damaged by smoke and debris, can be recovered and repaired.

The fire was confined to Room 204, which consists of four faculty offices and a conference room. While the building itself suffered no structural damage, the offices around Room 204 suffered extensive cosmetic damage.

A brick wall running perpendicular to the building's face prevented the spread of the flames.

"That brick wall saved the rest of the building," Holland said. "Doors were closed that were supposed to be closed. That did a lot to contain the fire."

Holland added that the 1948 construction featured independent ventilation systems rather than conventional duct work. This prevented the spread of smoke.

The building will be closed for at least two weeks so the affected sections can be cleaned and the entire structure deodorized, Wagner said.

The old Aerospace and Mechanical Engineering building is scheduled to be taken down after AME units move to the new complex at the corner of North Mountain Avenue and East Speedway Boulevard, said Sharon Kha, assistant to the president.

Seastone urged anyone with information about the fire or its cause to call 88-CRIME.

Wildcat reporter Charles Ratliff contributed to this report.