JACKSONVILLE, Fla. -

The Jacksonville Sheriff's Office is investigating what led to a crash that killed a 14-year-old boy Sunday morning in Mandarin.

The Jacksonville Fire and Rescue Department and JSO said they responded to a single-car crash on Mandarin Road, just south of Mandarin Forest Drive, just after 4 a.m.

When rescuers arrived, one of the passengers, Garrett Schaub, was dead, according to police.

Police said the car was heading north in the 12800 block of Mandarin Road at a high speed and failed to negotiate a right hand curve in the roadway. The car left the roadway and the front-end struck a large oak tree.

The driver was taken to a local hospital with serious injuries. The front right passenger sustained minor injuries and was not transported to the hospital. The right rear passenger was taken to a hospital with life-threatening injuries.

Schaub, the left rear passenger, died at the scene.

Police said speed and alcohol appear to be factors in the crash. They said the front right passenger was the only occupant wearing a seat belt.

Police said all occupants of the vehicle were juveniles. Police said their investigation is ongoing.

A makeshift memorial was created by friends and family at the scene. A sign that says "R.I.P. Garrett" is part of the memorial at the crash scene. There is also a lanyard from Mandarin High School placed on the memorial.