Officers responded to the scene, in the 6500 block of South Donovan Street, at about 1:30 p.m. after receiving a report of a high-speed crash.
Seattle fire officials said the driver apparently experienced a medical emergency before the crash and lost control of the vehicle.
The car rolled over three times at high speed and crashed into a tree on Beacon Hill Avenue South near South Cloverdale Street.
Aerial footage shot by KOMO's Air 4 showed the car was a mangled wreck of twisted metal after the crash.
The driver, identified as a man in his 50s with a history of diabetes, apparently survived the crash. He was rushed to the hospital with severe injuries.