Crews arriving at the one-story building in the 600 block of Mears Road in Warminster around 4:30 p.m. noticed heavy smoke and fire, according to Warminster police.
One man was left with facial and chest burns, authorities told 6abc.
"Everyone is asked to avoid the area as local roads surrounding this scene are closed so the fire department can work safely to extinguish this fire." Warminster police said in a statement.
The cause of the fire was not immediately known.
This story is developing.
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