At 17:01 BST on 8 September, the London Fire Brigade (LBF) was called to Heathrow Airport. LFB said it was responding to a “possible hazardous materials incident”.
Terminal 4 was evacuated, a spokesperson from the airport said, and passengers were seen waiting outside.
National Rail said trains had been unable to call at the Terminal 4 stop as emergency services were “dealing with an incident”.
What we don’t know is what the specific issue is, nor what caused it. We’re not seeing much disruption at Heathrow Airport as yet.