Two people involved in a crash near Knaresborough died at the scene on Monday morning, North Yorkshire Police has said.
Detectives are appealing for witnesses and dash-cam footage after the crash on the A59 between Flaxby and Goldsborough at around 8.30am.
A grey Mercedes, travelling from the A1(M) towards Harrogate, and a white Scania HGV were involved.
Two people in the Mercedes were pronounced dead at the scene.
Officers want to hear from anyone who may be able to help the investigation who has not already come forward.
They would also like to hear from anyone who saw the grey Mercedes car travelling between the A1(M) and Goldsborough, and from anyone with relevant dash-cam footage.
Call North Yorkshire Police on 101, and ask for the Major Collision Investigation Team, or email firstname.lastname@example.org, quoting reference 12190207840..
The road is likely to stay closed until at least 5pm on Monday.
Motorists are asked to avoid the area, and thanked for their patience.