The man who died in a two-vehicle smash at Burnley Road, Halifax, on Monday has been named as Dasingee Francis, 76, of Southampton.
He died from natural causes after suffering a medical attack.
Mr Francis was driving a red VW Polo when it was in collision with a blue Audi around 11.10 am.
The road was shut between King Cross and Tuel Lane while emergency services dealt with the incident.
A passenger in the Polo suffered serious, but non-life threatening injures and was taken to the Huddersfield Royal Infirmary.
A man and woman, both aged 67, in the Audi, received minor injuries and have been released from hospital.
Sergeant Carl Quinn of the Major Collision and Enquiry Team MCET said: “We are appealing for any witnesses to the incident, in particular anyone who saw the Volkswagen being driven along Burnley Road prior to the incident to get in touch on the non emergency number 101.”