Burton Fire District Firefighter/EMT Stuart Hardy, 31, suffered the emergency while at the scene of crash.
He was taken to Beaufort Memorial Hospital and later flown to the Medical University of South Carolina in Charleston.
Firefighters have been at his side since the incident while neighboring departments have answered calls.
Hardy died early Thursday.
Hardy, a former U.S. Marine, was the father of three daughters.
Funeral services will be announced soon.
