A 15-year-old boy was killed and three other teenagers were seriously injured early Thursday morning in a single-vehicle rollover crash on State Highway 6, according to the Texas Department of Public Safety.

Deadly Texas crash What we know: The crash happened at 2:20 a.m. near mile marker 348 in Eastland County.

According to the preliminary DPS investigation, 19-year-old Maddox Gilliam of Cisco, Texas, was driving a 2014 Chevrolet Tahoe eastbound at an unsafe speed.