Essex police have arrested two lorry drivers on suspicion of dangerous driving following a multiple pile-up on the M25 near Lakeside.
One person was killed and five more including a child were taken to hospital following the crash involving three lorries and five cars.
The collision happened between Junctions 29 and 30 shortly before 12:30pm. A section of the clockwise carriageway has been closed with traffic being diverted off and back on the motorway. The road is expected to be closed until later on Tuesday evening.