They say a utility pole snapped early Thursday afternoon at Electroline Corp on Route 611 in Plumstead Township.
The transformer struck a gas meter, which then ruptured the gas line, sparking a raging fire.
PECO crews rushed to the scene to cut the power, and that's when firefighters moved in.
However, the walls of the tool manufacturing plant collapsed, leaving the building a total loss.
No one was hurt.