UPDATE (10:00a): According to the California Highway Patrol a semi truck made an unsafe lane change, causing the crash.
Both drivers suffered minor injuries and were transported to a local hospital.
No one else was hurt in the crash.
All four southbound Highway 99 lanes will likely be shut down until noon.
Both semi trucks were carrying water.
UPDATE (9:05a): CHP said the driver is being taken to Delano Medical with minor injuries.
UPDATE (8:39a): The California Highway Patrol has put a hard closure in place on southbound Highway 99. Traffic is being diverted north of the crash onto Pond Rd.
A semi-trailer crash along Highway 99 near Elmo Hwy in McFarland has blocked traffic.
All southbound lanes of Highway 99 are blocked. The California Highway Patrol is on scene, working to clear the roadway.
It is unknown if there are any injuries.
According to the California Highway Patrol Dispatchers website, the semi-truck was swerving across the lanes prior to the crash.
23ABC is headed to the scene, check back for updates.