RICHFIELD, Idaho (AP) — Law enforcement officials say the driver of a school bus that rolled over and injured more than a dozen students was either asleep or fatigued before the crash occurred.

According to an initial report by Idaho State Police released Thursday, 67-year-old Richard Mecham of Carey may have also been distracted. The report says charges against Mecham are pending.

On April 18, junior high students from Carey School were on their way to a track meet in Gooding when their bus crashed about 125 miles (201 kilometers) southeast of Boise on U.S. Highway 26. Mecham drove off the right shoulder, overcorrected and rolled the 2011 school bus.

Twelve students were hospitalized. All were released the next day. Superintendent GwenCarol Holmes said in a letter sent to parents and students Thursday that Mecham is no longer employed by the school district.