Authorities say speed and alcohol likely contributed to a single-vehicle wreck late Wednesday night that claimed the life of a 34-year-old man.

According to a Forsyth County Sheriff's report, Clifton Leigh Palmer of Keithwood Court crashed his 2008 Chevrolet Silverado about 11:45 p.m. Wednesday on Castleberry Road, southwest of Cumming.

Sheriff’s Traffic Specialist Ron Tomblin said Palmer was traveling south near Whitlow Elementary School when the truck left the road and struck a power pole.

It then flipped twice before landing on its tires.

Palmer, who was traveling alone, was pronounced dead at the scene.

The wreck is under investigation, authorities said.