Upon arrival, the aircraft was immediately surrounded by firefighters who doused a small engine fire and boarded the aircraft. Though it's not immediately clear what caused the engine damage, aerial video from WCAU-TV in Philadelphia showed the engine cowling shredded and ripped away as well as major damage to the engine. In a press conference Tuesday night, the NTSB announced that one of the fan blades was missing from the engine and that investigators had found metal fatigue where the fan blade attached to the hub. Officials also said that a part of the engine cowling was found about 70 miles northwest of Philadelphia.