Sgt Colin Jenkinson of the roads policing unit added:
East of England Ambulance Service NHS Trust spokesman Gary Sanderson, who attended the scene where three men believed to be in their late teens and early 20s died after their car and an articulated lorry collided, said:
Anyone with information is asked to contact police on 101.
Three men believed to be in their late teens and early 20s have been killed after their car and an articulated lorry collided.
A third person was taken to hospital with serious injuries following the crash on the A10 near Turnford, a spokesman for Hertfordshire Police said.
The accident happened on the northbound carriageway at around 2.15pm when a Vauxhall Corsa collided with the Mercedes Artic lorry.
The driver and two passengers in the Corsa died at the scene while a third passenger was taken to the Royal London Hospital, Whitechapel, by air ambulance with serious injuries.
The driver of the lorry was not injured.