Seven fire companies from Genesee, Wyoming and Erie counties responded to 483 Alley road in Darien for a workshop fire about 10:05p.m. on Tuesday night.
The fire went to a second alarm as the blaze could be seen from Broadway road.
Fire crews fought the fire in a defensive mode as the metal framed building collapsed over the contents inside. Four trucks could be seen smoldering as fire crews ripped the metal walls away from the structure to help put the fire out.
The owner of the building works in electrical construction and used the building to store vehicles and equipment.
Fire investigators are looking for the cause of the fire.
The building and its contents are a total loss.
No one was injured in the fire.