CANBERRA, Australia, Sept. 22 (UPI) -- Blackened debris possibly from Malaysia Airlines Flight 370 found off the east African coast recently does not necessarily indicate the plane was doomed by a catastrophic fire, investigators said Thursday.
Investigators with the Australia Transport Safety Bureau said in an update that dark coloration on the two pieces of composite, which may have indicated fire, is actually the reaction of an applied resin on those pieces.
"The dark color of the coating was an inherent property of the resin, and not the result of exposure to heat or fire," the ATSB said. "The lighter grey surface areas resulted from a thinner film of the same resin applied over an off-white background."
Flight 370 disappeared in March 2014 and investigators believe it crashed somewhere in the Indian Ocean. The plane's wreckage has not yet been found but miscellaneous pieces of debris have washed ashore. All 239 people on board are presumed dead.
The other conclusion in Thursday's report said, "three small marks on the larger item were indicative of localized heating. The age and origin of these marks was not apparent."
The ATSB, though, has not yet confirmed that the pieces of debris are definitively from the missing Boeing 777. A wreckage hunter turned over the pieces of debris to Australian investigators last week.