A converted semitrailer that crashed on a Kansas highway and killed five people was driven by a 17-year-old boy with a provisional license.

Adam Kerber was behind the wheel of the Freightliner truck when it broke through a guardrail and went into a ravine Sunday morning near Williamsburg, about 70 miles southwest of Kansas City, Mo.

Minnesota authorities say Kerber's license includes several restrictions, including that all occupants of his vehicle wear seat belts where available. Only two of the 18 people aboard were belted in, but it wasn't clear if belts were available for those passengers riding in the trailer.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.

Authorities say five members of a Minnesota family killed in a motor home crash in northeast Kansas weren't wearing seatbelts.

The crash, which also injured 13 people, occurred Sunday morning on Interstate 35 when a Freightliner box truck pulling a trailer hit a guardrail and a concrete bridge rail before crashing into a ravine near Williamsburg, about 70 miles southwest of Kansas City, Mo.

The Kansas Highway Patrol said all 18 people were inside the vehicle, which had living quarters inside.

The patrol's report on the crash says all five of the family members killed in the accident weren't wearing restraints. The patrol report also said only two of the injured, including the 17-year-old driver, were wearing seatbelts.

At least two of the injured were in critical condition Monday.