Investigators believe an exhausted driver is to blame for an accident Saturday evening.
The crash happened just before 6 p.m. on Lincoln Highway on the west side of Nevada.
Police Chief Ricardo Martinez says they believe the driver fell asleep, lost control, and struck the side of the bridge going over Indian Creek.
The man was airlifted to a Des Moines hospital with what authorities are describing as non-life threatening injuries.
One in nine Americans admitted to falling asleep behind the wheel over the past year according to a National Highway Traffic Safety Admiration survey.