A man died after his lorry overturned and caught fire on the M25.
More than 35 firefighters battled the blaze after being called to the incident between Potters Bar and Enfield at 12.15pm.
Severe delays built up between Junction 24 (Potters Bar) and Junction 25 (Enfield) as six fire trucks attempted to tame the inferno.
A spokesman for the London Ambulance Service said: "We were called at 12.18pm to reports of a road traffic collision involving a lorry on the M25 (junction 25).
"We sent an ambulance crew, single responder in a car, a duty officer and our hazardous area response team to the scene.
"Sadly one person was dead at the scene."
A diversion is now in operation by leaving the M25 at junction 23 on to the A1 Barnet Bypass southbound to the A406 then to the A10 to rejoin the M25 at J25. Congestion is as far back at junction 22.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here