http://news.bbc.co.uk/1/hi/england/london/6701751.stm

Now it remains to be seen if there actually was a fire or if it's just a slow news day.

From listening in, the crew did not seem overly concerned about inspections etc. from the Fire Service after landing - taxied clear of RW and quick low key chat on 121.6, then taxied on. ATC did however say they had declared a Mayday... If it was even a Fire indication I would therefore think it went out pretty quickly ;)
LHR ATC as ever "coped" v well - a quick additonal orbit or 2 here there and everywhere to let him slot in... Just as well - gave BA a chance to get dispatchers to stand and guidance on :rolleyes: