Ross Park Mall was evacuated Sunday due to fire concerns.
Reports indicate there was smoke in the ventilation system due to a problem with an air handler.
Reid Carter told KDKA Radio's Larry Richert the fire alarm activated and he heard a loud bang that sent people to the exits.
“Security was surrounding the place, people were in panic,” said Carter. “People were running to their cars, cars were speeding away.”
Rumors about a shooting were incorrect.