A semi ran off Interstate 40 and ended up in Lake Eufaula Thursday morning.
According to the Oklahoma Highway Patrol, the incident actually involved two trucks.
The OHP says the driver of one truck may have fallen asleep and the second driver overreacted.
Both trucks ran off the highway, but the first truck crashed through a guard rail and ended up with its cab in the water.
The OHP says the crash did not appear to be weather-related.
Photos posted on the McIntosh County Sheriff's Office Facebook page show the driver of the truck in the water being carried to an ambulance, but the OHP says no one was seriously hurt.