TWA800. Not heating caused. Empty, 'fume filled' Center tank, and some 'arcing' internal wires, as I recall. Much talk of the need for 'inerting' tanks, like the 787 does. The need for inerting cropped up due to the extensive use of composites. No 'Faraday Cage', no 'bonding' (in the sense of 'electrical', not composite.)