The McDonalds on Hover Street was evacuated due to smoke in the building.
According to Longmont Public Safety spokesperson Robin Ericson, there is not much information about what happened at the store at this time.
Longmont Fire Services responded to the store around 1 p.m. on Wednesday. While in route, dispatch reported that the building had smoke in it and patrons were being evacuated.
It was later discovered that a fire had begun in the women's bathroom. An investigation is underway and video from a security camera is under review, Ericson said.