Sussex Police is appealing for witnesses after a car was in collision with a garden wall and house in Portslade yesterday afternoon (May 15).
The incident, at around 4.20pm, involved a silver Honda Jazz car and took place on Oakdene Avenue at its junction with Oakdene Gardens, police said.
Officers said the 85-year-old driver, who was a local man, was suspected to have suffered a cardiac arrest, and was taken by ambulance to the Royal Sussex County Hospital, where he remains in a critical condition.
There were no other casualties, according to police.
Anyone who saw what happened or who may have other information concerning the incident is report online or call 101 with the reference 1045 of 15/05.