Falmouth Firefighters arrived to the scene near the Waquoit Bay National Estuarine Research Reserve at 4:38 p.m. and found the Chevy Impala engulfed.
Cpt. Michael White, of the Falmouth Fire Department, said the vehicle had two doors open and the driver could not be found immediately.
White said that Falmouth Police found a man they believe to be the driver about 300 yards from the accident.
The man refused transport to the hospital at the scene, but later complained of back pains and was taken to Falmouth Hospital for evaluation.
Falmouth Police would not comment on the accident.
The accident remains under investigation.