KENOSHA, Wis. -- Kenosha County authorities are continuing to investigate a crash in which a semitrailer slammed into a school bus in southern Wisconsin Friday afternoon.

The crash on state Highway 50 near Silver Lake left five people seriously injured, including a boy stepping off the bus, two other children, the trucker and the bus driver. Two of the children were airlifted to Children's Hospital of Wisconsin in suburban Milwaukee.

The Kenosha County sheriff's department said that only one child and the 51-year-old semitrailer driver remained hospitalized Saturday.

The sheriff's department said the child has a fracture but is expected to be released Saturday. The semitrailer driver is expected to remain hospitalized for the coming days.

There were 14 children on the bus from Wheatland Center Grade School, ranging from 6 to 12 years old. Authorities said that all 14 children aboard had some injury, but only three were seriously injured. The drivers of both vehicles were also seriously injured.

Sheriff David Beth said the 51-year-old trucker apparently was drinking a soda and was either coughing or choking on it when his rig came over a rise and ran into the bus, which had its emergency lights flashing.

Emergency personnel arriving at the scene found children scattered in the grassy areas of the roadside. The front end of the semitrailer was smashed in, and the bus was pushed at an angle across part of the divided four-lane highway. Neither vehicle tipped over.

Authorities said they haven't yet determined what, if any, charges will be filed.