Harrogate, Ripon and Knaresborough Fire crews were to sent today (14 July 2016) to a property on James Street in Harrogate.
Staff had reported a smell of smoke from within the high rise commercial property.
Everyone was out of the building on the arrival of fire service and a search of the building located a small area of fire, that was already out.
An investigation has concluded that the fire was most likely caused by sunlight reflected from a mirror onto a box.