Authorities say a hot light bulb that fell onto cardboard sparked a massive blaze at the former Bethlehem Steel site outside Buffalo.
WGRZ-TV reported that a Lackawana city official said the fire started early Wednesday when a hot bulb fell on combustibles at the industrial site just south of Buffalo.
TV news footage and video images showed a large building engulfed in flames - massive clouds of black smoke billowing - the roof of the building collapsing. The flames have since diminished, but smoke continues to spew from the building, which includes a recycling business.
Authorities told residents of Lackawanna and neighboring communities to stay in their homes.
No injuries have been reported.
© 2016 AP