A kitchen fire broke out at the early Friday, causing smoke and soot damage throughout the restaurant, the reported.
The fire originated around 7 a.m. in the mechanics under the grease trap, said Fire Department spokesman Lt. Troy Donlin.
Fire fighters were able to extinguish the blaze, but the restaurant was closed for a time because of soot and smoke damage throughout the restaurant, Donlin said.
It was not clear as of 3 p.m. whether the restaurant had reopened. A call to Wendy's was not answered.
The mechanical system of the grease trap was so damaged that investigators said it was unlikely that the cause could be discovered, Donlin said.