MOORHEAD, Minn. (AP) — The Minnesota State Patrol says a semitrailer truck was the probable cause of a June rollover that killed two teenage brothers from Moorhead last June.

KFGO-AM  says the patrol released its report on the crash on Interstate 94 that killed 18-year-old Zach Kvalvog and his 14-year-old brother, Connor.

The Kvalvogs and two other boys were heading to a basketball camp in Wisconsin when the pickup that Zach Kvalvog was driving went into the median and rolled near Dalton.

A surviving passenger told investigators that the semi-truck was "extremely close" to the pickup moments before the crash. The truck has not been found.

(© Copyright 2015 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.)