The flames are out, but firefighters remain on the scene of a grass fire that torched more than 50 acres of a swampy area near Independence City Hall Sunday night and into early Monday.

Crews from the Maple Plain Fire Department and West Hennepin Public Safety responded to the rapidly growing blaze, which started around 8:30 p.m. in the center of the 160-acre swamp covered in cattails and brush, authorities said.

No property was damaged and no injuries were reported.

Highway 12 between County Road 90 and County Road 83 was closed for more than four hours overnight as crews from multiple agencies battled the fire. The highway reopened for Monday morning's commute, the West Hennepin Public Safety Department said.

Several local roads in the vicinity of the fire also were closed.

It was not immediately known how the fire started.

Tim Harlow • 612-673-7768