A medical emergency may have caused a crash that killed a semitrailer truck driver Thursday in Fergus Falls.

Samuel M. Hoffhein, 62, of Rhinelander, Wis., was driving on W. Lincoln Avenue about 8:05 p.m. when his 2007 Kenworth semi truck struck a power pole as it left the road at N. Tower Road, the Minnesota State Patrol said.

Hoffhein was taken to Lake Region Care Center in Fergus Falls, where he later died, the patrol said.

Hoffhein was the only occupant of the truck and was not wearing a seat belt, the patrol said.

Preliminary information indicates that Hoffhein "possibly suffered a medical emergency before running off the road to the right," said Sgt. Jesse Grabow of the State Patrol.

No other vehicles were involved in the crash, he said.