OKLAHOMA CITY - Emergency crews were called out to the scene of a serious crash on the far southwest side of the metro, Thursday morning.

Several agencies were called in to assist with a reported two-vehicle head-on crash, in the area of S. Mustang Road and SW 59th Street.

According to police, the crash was caused when the driver of a black Honda Accord, traveling southbound on Mustang Road, drifted left of center and collided head-on with a vehicle heading northbound. The driver of the Honda was not wearing a seatbelt and was ejected from the vehicle. That person was transported from the scene to OU Medical Center in very critical condition. It is unclear what caused the driver of the Accord to drift into oncoming traffic.

Two people in the northbound vehicle were also transported from the scene, but authorities tell News 9 their injuries are non-life threatening.

Authorities had to shut down S. mustang Road, between SW 59th Street and SW 44th Street, while crews worked the scene.

Keep checking with News 9 and News9.com for more information.