One person is dead and another seriously injured following a one-vehicle accident in Green Lake County. The accident happened this morning on Sunnyside Road, about one mile east of Green Lake, in the Town of Brooklyn. Preliminary investigation shows a van was eastbound on Sunnyside Road when it left the roadway and struck a driveway embankment. The van then vaulted over the embankment, struck a utility pole, struck a second embankment and rolled over. Both the driver of the van, a 49-year-old Ripon man, along with the passenger, a 30-year-old Green Lake man, were ejected from the vehicle. The Ripon man was pronounced dead at the scene. The Green Lake man was transported to a local hospital then flown by flight for life for further medical attention. His condition is currently unknown. Police say speed is a factor as to the severity of the crash. Names of the two people involved have not yet been released pending notification of family members. The accident remains under investigation.