After examining debris from the Air France jet crash that killed 228 people en route from Rio de Janeiro to Paris, Brazilian search crews have ruled out the possibility that a bomb took down the plane. Reuters reports that the crash debris was spread over 55 miles of ocean, and included large fuel stains in the water, which suggest that the plane wasn't burned and therefore that a bomb was not what caused the crash. Experts think that extreme turbulence or decompression during a storm are more likely. The real cause of the tragedy may never be definitively determined. Although France has sent out a small submarine to try to recover the flight data and voice recorder from the floor of the ocean, finding the items may prove difficult as the crash site is over a particularly deep and mountainous segment of ocean.