PLATTEVILLE, Wis. -

A structure fire on Highway 151 in Platteville caused significant damage to the local Culver's franchise.

Platteville police officer Kris Purkapile said the department received a call at 4:20 a.m. Saturday from an alarm company for a tripped motion detector.

Platteville Fire Chief David Izzard said officers responded to the Culver's at 375 Highway 151 and first saw smoke and flames near the kitchen. All the doors were locked and no one was inside. The fire chief said it appeared the fire began in the kitchen and smoke activated the motion detector.

Izzard said the estimate of $500,000 damage to the restaurant is early and the number could go up.

Purkapile said the fire department had the blaze under control just after 10 a.m. and firefighters were working to put out hot spots.