UPDATE (5:49 a.m.): All lanes of Southbound 99 near Lerdo Highway have reopened after nearly eight hours. Two lanes were shut down to help cleanup the scene following Tuesday night's crash between two big rigs. 

The cause of the crash is under investigation, according to CHP. Officials say the semi truck that pulled over may have not been all the way out of the lanes, which could have potentially caused the crash. 

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California Highway Patrol officers are on scene of a crash involving two semi trucks on southbound Highway 99 near Lerdo Highway. 

CHP officials said just after 9:30 p.m. a semi truck driver carrying corn flour pulled over to the right hand shoulder to rest and another semi truck carrying cattle feed came up behind him and rear-ended the semi truck.

The driver who hit the parked semi truck was taken to the hospital with minor injuries. 

Two lanes of southbound Highway 99 are closed as crews investigate and clean up the crash. Cal Trans is on the way to the scene. Officials expect those lanes to be closed for four to six hours. 

23ABC has a crew on scene, be sure to tune into 23ABC News at 11 p.m.