Three people died after a crash on the M25 near Waltham Abbey in Essex.
The fourth person was injured and is currently being treated in hospital.
The three vehicles crash involved a Mondeo, a minibus and a lorry.
Two people were arrested following the crash on suspicion of causing death with their dangerous driving.
The motorway was shut in both directions for hours, and drivers were asked to avoid the area.
It reopened at 5.10 am today.