An industrial fire that destroyed a plant and damaged at least one other building in Leetsdale is under investigation by the Allegheny County fire marshal’s office. Emergency and company officials say workers at a warehouse in the Leetsdale Industrial Park were pouring hydraulic fracturing chemicals into a production tank Tuesday when the fire started, forcing residents from more than 70 nearby homes for several hours and injuring several people. Parts of Beaver County were affected due to the thick heavy smoke along the river, leading to an early dismissal for students at Hopewell Area High School. Beaver County Commissioner spoke with Beaver County Radio newsman Pat Septak, saying he was able to stay on top of the situation by receiving continuous updates from Beaver County Emergency Services Director Wes Hill. The evacuation order was lifted late yesterday afternoon after the chemical fire was contained.  The case has been turned over to Allegheny County investigators but officials say it could be days before more information is released.