A suspicious fire at Eagan's historic town hall Sunday morning damaged a roof, wall and several irreplaceable artifacts.

More than 40 firefighters from four of Eagan's five fire stations responded to the two-alarm fire, which was under control in about 15 minutes, said city spokesman Tom Garrison. The fire started outside the back of the wooden building, which was built in 1914.

Garrison didn't provide any details on why the fire is considered suspicious. Nobody was injured.

A police officer exiting the police department, which is across the street from the town hall on Pilot Knob Road, noticed the fire at about 5 a.m. An incident commander at the scene told Garrison the building probably can be rebuilt.

The city was gearing up to celebrate the 100th anniversary of the town hall, which was used for business until 1965. This was before Eagan became a city in the 1970s, Garrison said. The hall is opened occasionally throughout the year, when visitors can see a potbelly stove and various artifacts hanging on the walls. Original glass in the windows was destroyed, he said.

Traffic was closed on Pilot Knob Road for several hours.

Eagan Historical Society vice chair Kim Hazel credited firefighters for salvaging as many historical items as they could.

"We are so grateful for what firefighters were able to remove," she said. "We've lost original photos and news clippings, some old town maps and original glass in the windows dating to 1914. These things are irreplaceable."

A reward is being offered for information that might help solve the case. Call the state arson hotline at 1-800-723-2020, the Eagan Fire Department or the Eagan Police Tip Line at 651-675-5799.