A man drove a car into a metal gate at the FBIs Pittsburgh field office early Wednesday in what authorities described as an intentional "act of terror."Donald Henson, of Penn Hills, Pennsylvania, allegedly rammed the gate of the main entrance around 2:40 a.m. with a white Toyota sedan before getting out and then grabbing an American flag from inside the vehicle and throwing it over the gate, FBI Special Agent in Charge Christopher Giordano said at a press briefing.Henson fled on foot after the crash and may be dangerous, Giordano added. It was not immediately clear if he was armed."We look at this as an act of terror against the FBI," Giordano said, per CBS. "This was a targeted attack on this building."This is a breaking news story and will be updated.