Emergency services were called after a car hit a block of flats in Northern Crescent, East Wittering, at 11.55am on Sunday.
The driver, a 53-year-old man from Weston-Super-Mare, Avon, is believed to have suffered a medical episode and lost consciousness before his Peugeot car went into the flats.
His passenger, a 48-year-old woman also from Weston-Super-Mare, suffered slight injuries. They both went to St Richard's Hospital, Chichester.Two other passengers in the car, a 15-year-old boy and a 13-year-old girl, were unhurt.
The vehicle caused structural damage to four flats in Windmill Court, with four residents having to leave their homes.