Environmental teams were called to a HAZMT scene near Whitehall on Wednesday.
According to officials at the Defense Supply Center (DSCC) along East Broad Street, a crew working to install a new gate was digging and struck a white powdery substance which then ignited and began to smoke.
Crews blocked Yearling Road shortly after 10 a.m.
Federal environmental crews planned to work through the night on Wednesday to determine what the powder was and to clean up the area.
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