A man fired a gunshot through the drivers' side window of a Pittsburgh Regional Transit bus in Pitcairn after boarding with another man Tuesday night, according to police.Watch the report in the video player above.The bus was heading inbound at Broadway Boulevard and Wall Avenue.No one was hurt. Police said both men exited the bus and ran away toward the Patton Street Bridge.Officers said that the shooter was wearing a black t-shirt and black pants, as well as red and gold shoes. Police estimate that the suspect is between 16 and 22 years old.Transit police are asking anyone who has information about the incident to contact them.