STILLWATER TOWNSHIP - (AP) - Authorities say an ambulance driver suffered a heart attack and died while transporting a man injured in a fatal house fire in northwestern New Jersey.

Authorities say the driver, whose name was not disclosed, crashed the ambulance early Tuesday while driving John Baer to the hospital.

Greg Mueller, Sussex County's first assistant prosecutor, says Baer's wife, Dorothy, was killed after a fire engulfed their Stillwater home. She was pronounced dead at the scene.

John Baer is hospitalized in intensive care, but further details on his condition were not disclosed.

Mueller says state police and county investigators are working to determine how the blaze started.