One person is dead another has been airlifted to Hamilton General hospital.

OPP say they are investigating a single vehicle rollover on the off ramp at highway 25. As a result traffic in the east bound lanes of the 401 near Milton came to screeching halt around noon on Sunday. The highway was closed for about 4 hours.

The 75-year-old driver was air lifted to Hamilton trauma centre with serious but non life threatening injuries. His 78-year-old female passenger was pronounced dead at the scene.