The Lake Mills Fire Department responded to a fire at Cummins Filtration in this city early Thursday morning.

Lake Mills Fire Chief Dave Anderson said at about 1:30 a.m. firefighters were dispatched to Cummins Filtration after an air compressor started on fire as a result of a mechanical problem. This set the sprinklers off, and upon arrival, the building was filled with smoke.

Employees were evacuated from the building, and firefighters worked to ventilate the area, Anderson said.

Crews left at 3 a.m. but were called back at 3:30 a.m. after the fire started up again and spread to the roof.

The fire chief said firefighters had to cut out a portion of the roof. They left around 5:15 a.m.

The fire came about a week after the company — the largest in Lake Mills, Iowa — announced it would cut about 400 jobs at the Lake Mills plant and shift them to San Luis Potosi, Mexico.

The cuts will occur in shifts between November 2009 and March 2010.