Flights to and from Heathrow have resumed after they were halted due to a gas leak near the airport.
No planes were taking off or landing at the west London airport after a gas pipe was ruptured by a digger at a construction site.
The British Airports Authority (BAA) said operations on the southern runway were temporarily halted, but had now returned to normal.
But it has warned passengers and staff of major traffic problems in the area.
The A30 Great South West Road closed between the A312 and Hatton Rd. The eastern "Perry Track" (Perimeter Road) is also affected.
The Heathrow Express is operating a normal service and the Piccadilly Line is also open, but is not stopping at Hatton Cross.
A BAA spokesman said: "Earlier this afternoon, a gas pipe on a construction site to the east of the airport was ruptured by a digger.
"For safety reasons, an exclusion zone has been set-up by the emergency services and roads around the area have been closed."