AUGUSTA, Maine — An Orono man died Tuesday afternoon after the pickup truck he was driving struck a school bus carrying a bus driver and three students, none of whom were injured, according to Augusta police.

The driver of the pickup was identified as 60-year-old Herbert LeBreton, Augusta police Lt. Christopher Massey said in a news release issued about 8:20 p.m.

After he was extricated from his 2012 Chevrolet Silverado, which was wedged under the bus, LeBreton was flown to Central Maine Medical Center, where he died from his injuries. Massey said it took paramedics and firefighters nearly an hour to remove LeBreton’s pickup from under the bus so that he could be taken to the hospital.

According to Massey, the accident happened about 2:15 p.m. on Riverside Drive, just south of Stevens Road. A 2013 school bus owned by First Student and being driven by Jessica Kanaris, 39, of Augusta stopped in the northbound lane to let students off when LeBreton struck it from behind.

Maine State Police are investigating the crash. State police motor carrier inspectors also were called in to inspect the school bus, Massey said. The accident closed the road for about two hours, after which it was reduced to one lane for two more hours.

The cause of the crash remains under investigation, Massey said.