Years ago, MD87 out of Heathrow. Taxing, lady next seat asks me how safe is flying these days. I reassure her that nothing ever happens here, day in, day out etc.etc., TWA Tristar ahead of us starts to take-off, aborts halfway down runway. Doors and slides come out, pass evacuate 'cos it's on fire!!!!. [Air conditioning problem}. She doesn't speak to me again. Aircraft some years later burnt itself to destruction on the ground.