Discarded smoking material likely cause of Flight 93 memorial fire

SHANKSVILLE, Pa. - Discarded smoking material is strongly suspected as the cause of an October 2014 fire that struck the Flight 93 National Memorial, according to a report released on Saturday.

The National Park Service report also said landscaping mulch that was too close to the building and flammable decking material hastened the spread of the fire, which destroyed three of four buildings at the 9/11 memorial.

Several weeks after the fire, state police fire investigators noted that while there was no obvious ignition source, "a cigar/cigarette disposed of in the mulch bed could not be ruled out," the report said.

The blaze destroyed hundreds of original photographs and items found at the crash site that were linked to the passengers and crew of the plane.