Two people were killed and five others injured after a tractor trailer lost control and drove into oncoming traffic on a California highway.

The accident occurred on around 2:30 p.m. on Wednesday afternoon in La Mesa, California.

According to authorities, a Swift Transportation tractor trailer was headed south on Route 125, when it veered out of its lane and broke through a highway barrier, cleared two lanes of oncoming traffic, and broke through another barrier before striking two vehicles on the eastbound I-8 connector ramp.

The tractor trailer initially struck a Chevrolet Aveo, and the impact sent both vehicles into a dark Kia Sorento.

Two people inside the Aveo were killed. A mother and her two young children, ages 4 and 6, were inside the Kia Sorento. The mother and 4-year-old suffered minor injuries. The 6-year-old suffered spinal injuries and underwent emergency surgery.

The female driver of the big rig and a male passenger who was in the sleeper berth suffered moderate but non-life-threatening injuries and were taken to a local hospital.

The connector ramp was closed for several hours, but has since reopened. Police are continuing their investigation on Thursday morning and are trying to determine the reason that the tractor trailer lost control.

Local Fox-5 news captured the following aerial footage from the scene.