The Greene County Sheriff's Department and Indiana State Police are investigating a single-vehicle, fatal accident that occurred about 1:35 p.m. Wednesday at County Road 100 South and County Road 150 West.
The sheriff's department said driver Jason Giberson, 42, of Worthington, lost control of his 2006 Nissan Frontier pickup truck, which left the north side of the road and struck a tree.
Pronounced dead at the scene was passenger Aaron Henigman, 46, of Mattoon, Illinois.
Giberson was airlifted to Eskenazi Hospital in Indianapolis.
State troopers performed a crash reconstruction at the scene. Also assisting were Switz City Fire Department and Greene County Ambulance Service.