CARROLLTON, Ky. — Two children were killed and others were injured in a school bus accident that occurred here on Monday afternoon.

An initial investigation by the Kentucky State Police shows that the bus left the roadway for reasons that are unknown, partially overturned onto its side and then hit a tree. There were nine children on the bus at the time of the crash.

Two children were pronounced dead at the scene by the Carroll County coroner — they have been identified as Ryder Deitz and Caroline Tuttle, who were both 3-year-olds from Carrollton.

Three other children were flown to a children’s hospital in Louisville, Ky. A fourth child and the adult bus assistant were flown to the University of Kentucky Medical Center, while three other bus passengers were examined at the scene and released to their parents. The driver of the bus was uninjured.

On Tuesday, the Kentucky State Police received word that the three passengers at the children’s hospital were in stable condition. The bus assistant and the student at the University of Kentucky Medical Center were in serious condition.

Also on Tuesday, officials said that an accident reconstruction team was examining the bus to look for any mechanical issues or other factors that could have contributed to the crash. Another reconstruction team was at the crash site completing its investigation.

Officials said that the bus was equipped with seat belts, and it appears that they were in use by all occupants at the time of the crash.

Lisa James, superintendent of Carroll County School District, released a statement following Monday’s accident.

“A tragic bus accident has occurred involving children enrolled in the Carroll County School District,” she said. “The accident is still under investigation by local police authorities and school district personnel. At present, we are most concerned about the children involved and their families. Counselors and administrators have been present at area hospitals with families of some of the children involved in the accident.”

James also said that the school district will have counselors available at all of the district’s schools.

Other recent fatal school bus accidents:

• Girl fatally struck by school bus in Ark.

• 2 buses collide, 1 driver killed