A colleague in Japan said that NHK today is reporting statements from the investigators that fuel was seen to be leaking in large quantities from the oil drain ports on the right engine during taxi. Apparently, one port is on the lower edge of the pylon aft of the engine, and the other on the side of the pylon above the engine.
The pylon is being disassembled today. The NTSB, Boeing and CFM is in attendance.
The observation that the aircraft was just out of maintenance is pertinent. There have been incidents caused through misassembly of components such as O-rings and fuel lines. Think of the Eastern Airlines L-1011 incident in 1983, or the Air Transat A330 Azores glider in 2001. Jim Reason has a chapter in one of his books entitled "Maintenance cay Seriously Damage Your System".
He cites a couple of aviation examples, but they are both structural (AA 191 at Chicago in 1979, JL 123 at Mount Osutaka in 1985). So in answer to Gengis's question whether a hard landing can shake something loose, the answer is yes, if it has been misassembled. Just to be clear, I am not speculating on any cause here (we'll have to wait a couple of days to find out what the investigators think of the pylon assembly, I take it) but just reminding people of some history.
BTW, now that everyone has persuaded marciovp to grovel for asking whether there are procedures for dealing with such a fuel fire when the aircraft is docked at a terminal, can anybody answer his very reasonable and pertinent question?
Fire regulations, at least those concerned buildings in the vicinity of structures and vehicles containing highly flammable liquids, should in many countries be covered by rather stringent requirements concerning how to handle fires. Are there any generally-accepted procedures, or is it all just local ordinances? (I know a couple of aviation fire specialists I could ask if no one here can answer.)
PBL