Eyewitnesses describe the Kent pile-up involving more than 130 vehicles in thick fog this morning.
Around 200 people were hurt, and police said it was "truly miraculous" that no one was killed.
The accident began at 7.15am and continued for 10 minutes as cars and lorries crashed into each other.
Chief Inspector Andy Reeves, from Kent Police, said: "It is truly miraculous. Looking at the extent of the incident, the number of vehicles and people involved, the damage to some of those vehicles, I think we're all very fortunate there were no fatalities."