Three people were killed and another was seriously injured when two cars crashed head-on and exploded into flames.
A husband and wife are thought to be among those who died in the fire following the smash at a blackspot on the A27 at Selmeston, near Polegate.
The couple were in a Rover 416 at about 2am on Saturday when they were in collision with a Renault Clio travelling in the opposite direction.
Sussex Police released details about the victims this morning but have yet to reveal their identities.
The Clio driver was an 18-year-old man from Newhaven. The driver of the Rover was a 27-year-old man and his front-seat passenger a woman aged 22. Both were from Eastbourne.
All three died in the smash.
A man aged 26 from Eastbourne escaped from the back of the Rover and was taken to Eastbourne District General Hospital, where his condition is "comfortable".
All three emergency services attended the scene but a paramedic crashed en route and his car caught fire.
The road was closed for more than five hours while police tried to discover what had happened.
One officer at the scene said it was the worst crash he had attended in 18 years of policing.
The road, opposite a layby and about 400 yards west of the Barley Mow pub, was left scorched by the fireball.
A spokeswoman for East Sussex Fire and Rescue Service said firefighters had been very upset.
She said: "Dealing with a scene like this can be distressing. They were there for a while.
"It was a severe fire and both vehicles were alight but the crews put the fires out quite quickly."
A spokesman for Sussex Police said the victims would not be named until their families had been informed but it was believed they included a married couple.
He said: "This is a tragic accident and the families have to be informed in the correct way."
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 The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.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 hereComments are closed on this article