An 18-year-old man driving a McLaren the wrong way on Interstate 805 caused a fiery crash that killed three people just as the Thursday evening rush-hour commute was underway, according to the California Highway Patrol.

The man was driving southbound on the northbound I-805 HOV lane in excess of 100 miles per hour when he crashed, causing the fiery pileup around 4:30 p.m., the CHP said.

The McLaren crashed head-on into an SUV, killing the sports car driver and the two occupants of the SUV -- a 43-year-old mother and her 12-year-old daughter, according to the San Diego County Medical Examiner's Office.

Eight more people were injured in the crash that happened near the Governor Drive exit, according to the San Diego Fire-Rescue Department.

The crash happened during the evening commute, as traffic began to build, and several drivers swerved to get out of the wrong-way driver's path, witnesses told NBC 7.

"That car in front of me swerved, slammed and exploded within a fraction of second all I could do was hold on to my steering wheel and run over everything that exploded," Hector Puga said.

A Sig Alert was issued around 4:45 p.m. and all traffic for northbound I-805 was diverted to Mira Mesa Boulevard.

Authorities reopened two far-right lanes just before 10:45 p.m. after a six-hour closure of all lanes between La Jolla Village Drive and Mira Mesa Boulevard.

Initially, one person died inside a car, another was ejected and killed and the third had major injuries. That third person later died, according to the SDFD.

The identities of the victims have not been released and CHP investigators do not know why the driver drove the wrong way on the freeway.

All lanes of northbound I-805 were reopened by Friday's morning commute.