A46 Caistor bypass closed.
A fatal collision involved three Mercedes cars on the A46 Caistor bypass.
The bypass is closed southbound from Whitegate Hill to Nettleton Road.
Motorists have been urged to avoid the area.
Police released a statement.
Police confirmed that three people were seriously injured in the collision.
Later they confirmed a man thought to be in his eighties had died from his injuries.
Police urgently need witnesses to come forward, especially if they have dashcam footage of the crash.